I. INTRODUCTION

Micro light-emitting-diodes (Micro-LEDs), as a next-generation display technology, is rapidly advancing and attracting widespread attention. This technology utilizes micron-scale light-emitting-diodes (LEDs) as light-emitting pixel units, forming images through densely arranged LED arrays. It offers significant advantages in resolution, response speed, brightness, and service life. Micro-LED demonstrates tremendous application potential in fields such as Augmented Reality and Virtual Reality (AR/VR) and near-eye displays, automotive displays and smart lighting, as well as wearable devices ^{[1, 2]}.

Unlike traditional display technologies, Micro-LED directly integrates LED chips smaller than 100 micrometers onto a driving substrate to form a self-emissive display structure ^[3]. In terms of optical performance, its single-pixel brightness can reach tens of thousands of nits, enabling excellent visibility even in high ambient light conditions ^[4]. In dynamic display scenarios, Micro-LED's response speed far exceeds that of traditional technologies like liquid crystal display (LCD), allowing it to clearly render image details even at high refresh rates ^[5].

However, full-color Micro-LED display technology still faces numerous technical challenges. Since red Micro-LEDs require different epitaxial growth materials compared to blue and green Micro-LEDs, integrating red, green, and blue epitaxial layers on the same substrate is extremely difficult. The continued shrinkage of Micro-LEDs to achieve higher pixel densities means that even minor defects can significantly impact their subsequent light-emitting performance ^{[6, 7]}.

To achieve full-color display, massive transfer technology is essential. This involves efficiently and precisely transferring millions or even tens of millions of Micro-LED chips—each emitting only a single color (red, green, or blue)—from their respective growth substrates to a driving substrate. It also requires ensuring reliable electrical connections between these chips and the driving circuits to construct a high-density, high-precision display array ^[8]. This process involves the transfer of hundreds of thousands to tens of millions of Micro-LED chips, placing extremely high demands on the number of transfers, speed (millions per hour), precision, process yield (> 99.99999%), stability, and cost control. Existing massive transfer technologies—such as stamp printing ^[9], laser transfer ^[10], and fluidic self-assembly ^[11]—each exhibit notable limitations in practice. Stamping technology struggles with stamp adhesion control, resulting in yields that fail to meet mass production requirements. Laser transfer generates asymmetric shockwaves that affect placement accuracy, and uneven energy control can cause irreversible thermal damage to the chips. Fluidic self-assembly has difficulty achieving high-density, tightly packed arrangements, limiting its applicability in high-resolution displays ^[12].

Blue Micro-LEDs combined with a quantum dot (QD) color conversion layer can efficiently convert a portion of the blue light into red and green light, thereby enabling full-color display ^[13]. By precisely controlling the size and composition of the quantum dots, light at different wavelengths can be emitted, covering a wider color gamut. In micro-display applications such as AR/VR, this technology helps high-pixel-density panels achieve more accurate red and green colors and more natural color transitions. However, the technology still faces challenges: it is difficult to synthesize high-quality quantum dots with stable and uniform optical properties, and the mainstream synthesis methods remain time-consuming, costly batch processes. These issues represent key challenges to achieving its widespread application ^{[14- 16]}.

Additionally, in terms of performance, there are significant differences in light-emitting efficiency among red, green, and blue Micro-LEDs, particularly with the quantum efficiency of red and green being notably lower than that of blue ^[17]. These key technical bottlenecks severely hinder the commercialization of Micro-LED display products.

Another type of solid-state semiconductor light source, the organic light-emitting diode (OLED), is an organic light-emitting technology composed of multiple functional thin-film layers ^[18]. OLEDs achieve high brightness, high efficiency, and high contrast without requiring a backlight, while also offering wide viewing angles, fast response times, and excellent color accuracy ^[19]. Thanks to these advantages, OLEDs have become the preferred choice for modern display devices such as high-end smartphones and ultra-thin TVs, and they also show great potential in emerging markets like automotive displays and wearable devices ^[20].

Currently, red and green phosphorescent materials in OLED technology have achieved stable commercial applications, with external quantum efficiencies exceeding 35%, demonstrating outstanding light-emitting performance. However, blue phosphorescent materials still lag behind in overall performance, especially in terms of lifetime and efficiency ^{[21, 22]}. Due to the shorter wavelength of blue light, which corresponds to higher photon energy, the organic materials in blue OLEDs must withstand greater energy, leading to reduced material stability, accelerated aging, and shorter operational lifespans.

Achieving efficient, high-color-purity emission in the blue wavelength range is particularly challenging, and such devices also exhibit significantly shorter operational lifetimes compared to other types of materials ^[23]. These performance shortcomings of blue OLEDs negatively impact the overall quality of full-color displays.

This study aims to overcome the current technical bottlenecks in full-color display solutions for both Micro-LED and OLED. Based on existing fabrication processes, We innovatively leverage the commonalities in light-emission mechanisms and device architectures between Micro-LEDs and OLEDs. We propose a novel passive-driven full-color display solution: integrating blue Micro-LED subpixels with red and green OLED subpixels on the same substrate. This approach eliminates the need to separately transfer red, green, and blue pixels from their individual growth substrates to a common driving substrate, thereby simplifying the manufacturing process and significantly reducing costs. Furthermore, this design capitalizes on the high light-emission efficiency of blue Micro-LEDs and the superior stability of red and green OLEDs, providing a new technological pathway for the development of full-color display devices.

II. EXPERIMENT

A GaN-based blue multiple quantum well (MQW) LED epitaxial wafer grown on a 4-inch sapphire substrate was used to fabricate the Micro-LED array, with designated evaporation areas (sizes: 70 $\times$ 90 $\mu$m$^2$ and 50 $\times$ 70 $\mu$m$^2$) reserved for the deposition of red and green OLEDs. On this epitaxial wafer, two blue Micro-LED arrays of different sizes were fabricated on the same epitaxial wafer, one featuring 20 $\times$ 70 $\mu$m$^2$ pixels in an 8 $\times$ 16 array, and the other featuring 40 $\times$ 90 $\mu$m$^2$ pixels in a 16 $\times$ 18 array.

Fig. 1. Schematics of the pixel array atructure.

We successfully fabricated passive matrix (PM) display devices using blue Micro-LEDs with two different mesa sizes on a 4-inch blue epitaxial wafer. By integrating red, green, and blue subpixels fabricated on the same substrate, we avoided the complexity of massive transfer processes. Fig. 1 shows the structure of the designed circuit. Each subpixel consists of a blue Micro-LED connected in reverse parallel with a green OLED, along with an independently connected red OLED of the same polarity. After completing the fabrication of the Micro-LED passive matrix devices, Pre-alignment and precise alignment calculations were performed to define the evaporation areas for red and green OLEDs prior to the fine metal mask (FMM) process Subsequent device debugging further ensured alignment accuracy, after which we completed the multi-layer evaporation process for the red and green OLEDs. Ultimately, we achieved the integrated array of blue Micro-LEDs and red and green OLEDs on the same substrate.

In addition, this paper provides a systematic analysis and study of the photoelectric performance of the two different sizes of blue Micro-LEDs and the red and green OLEDs that were fabricated, laying the foundation for future optimization and application.

Fig. 2. Fabrication process flow of the Micro-LED device. (a) Wafer, (b) mesa and ISO etching, (c) sputtering of ITO, (d)fabrication of column electrodes, (e) SiO$_2$ deposition, and (f) fabrication of row electrodes.

Fig. 2 illustrates the manufacturing process flow for the Micro-LED device. Inductively coupled plasma (ICP) etching technology was employed to create isolation trenches with a depth of 5 $\mu$m on the epitaxial wafer, achieving electrical isolation between individual pixels. Subsequently, a 75-nm-thick indium tin oxide (ITO) transparent conductive layer was deposited on the sample surface via magnetron sputtering, serving as the anode material for the red and green organic light-emitting diodes (OLEDs). The ITO regions exposed by photolithography and development, were selectively etched using an ITO etchant to form the electrode patterns on both the mesa structures and the OLED deposition areas. The n-type electrodes, with a total thickness of approximately 2 $\mu$m and composed of a multilayer structure (Cr/AlCu/Ti/Pt/Au/Ti), were fabricated using electron beam evaporation. To effectively prevent short circuits caused by intersecting row and column electrodes, and to avoid potential shorting of the light-emitting regions due to environmental contaminants such as moisture and dust, a silicon dioxide (SiO$_2$) insulating layer was deposited on the sample surface via plasma-enhanced chemical vapor deposition (PECVD). Following insulation layer deposition, ICP etching was used to open the p-electrode contact windows as well as the evaporation areas for the red and green OLEDs. Finally, the p-type electrodes, consisting of the same materials and deposited in the same sequence of thicknesses as the n-type electrodes, were fabricated via electron beam evaporation. These p-type electrodes were then interconnected with a flexible printed circuit (FPC).

Through the above fabrication steps, the passive matrix (PM) Micro-LED display array was successfully fabricated. This process achieved pixel isolation and established the electrode interconnection structure required for array-based display devices.

The PM (passive matrix) device designed in this study integrates Micro-LEDs and OLEDs in a hybrid configuration, with its pixel array arranged in a repeating RBGGBR sequence. As a result, the vacuum deposition of the red and green OLEDs requires precise alignment. Given that the prepared Micro-LED epitaxial wafer is 4-inche in size, while the laboratory's existing evaporation equipment is designed for 8-inch substrates, a specialized adapter plate was specially designed to securely hold the 4-inch epitaxial wafer.

Using the entire 4-inch blue Micro-LED epitaxial wafer as the substrate, an ITO (indium tin oxide) thin film was deposited to serve as the anode. Subsequently, the various organic layer structures were constructed via the evaporation process, ultimately completing the fabrication of the OLED devices.

Prior to evaporation, the epitaxial wafer underwent a series of surface treatments to ensure optimal deposition conditions. The procedure was as follows: A four-step cleaning process was employed, sequentially using deionized water rinsing to remove physical adsorbates, a five-minute acetone immersion to eliminate chemical residues, isopropyl alcohol cleaning, and nitrogen blow-drying. Following surface pretreatment, the sample was placed in a nitrogen-filled oven and baked at 120 $^\circ$C for one hour, a step specifically designed to effectively remove both surface-adsorbed and internally trapped moisture. Through the above treatments, the surface morphology and chemical state of the epitaxial wafer were significantly improved.

Subsequently, the treated epitaxial wafer was mounted onto the 4-inch wafer adapter plate and covered with an 8-inch evaporation substrate. Manual pre-alignment was then performed using a microscope to ensure that the metal shadow mask was accurately aligned with the red and green OLED deposition regions. The positional information of the mask at this stage was carefully recorded.

After pre-alignment, the assembled 8-inch evaporation substrate was loaded into the CIC evaporator. Based on the previously recorded manual pre-alignment data regarding the mask position, multiple realignment procedures and compensation calculations were carried out until precise alignment was achieved.

After alignment, the functional layers were sequentially deposited as illustrated in Fig. 3. The blue Micro-LED structure began with the deposition of a 75-nm-thick ITO anode layer. This was followed by a 5-nm-thick HAT-CN(1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile) layer as the hole injection layer (HIL) and a 50-nm-thick NPB(N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine) layer as the hole transport layer (HTL).For the red and green organic emitting layers, a 40-nm-thick CBP(4,4'-bis(carbazol-9-yl)biphenyl) host material was used. The red emitting layer was doped with 16% AT5441 dye, while the green emitting layer was doped with 10% Ir(ppy)$_3$(tris(2-phenylpyridine) iridium) complex. Subsequently, a 20-nm-thick TmPyPB(1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene) electron transport layer and a 1-nm-thick LiF electron injection layer were deposited. Finally, a 100-nm-thick aluminum cathode layer was thermally evaporated to complete the device structure.

Fig. 3. Evaporation process flow for red and green OLEDs (a) green OLED evaporation (b) red OLED evaporation.

After the evaporation process was completed, the samples were transferred to an inert atmosphere glove box integrated with the evaporation system. Using a spin coater, an epoxy-based ultraviolet (UV) curable adhesive was uniformly applied along the predefined encapsulation boundary of the OLED device and the bonding area of the glass cover plate at a constant speed. A 22 mm $\times$ 22 mm glass cover plate was then placed over the device. Upon exposure to UV light, the adhesive layer underwent cross-linking and curing, achieving a robust bond between the substrate and the cover plate. This glass cover plate functions as an encapsulation barrier, forming a highly hermetic protective structure that effectively blocks the penetration of moisture and oxygen. This significantly enhances the environmental stability of the device and extends its operational lifetime.

Following the encapsulation process, the chip electrodes were electrically connected to a pre-fabricated driver circuit board via a flexible printed circuit (FPC). This interconnection was achieved using micron-sized conductive particles, ensuring reliable vertical (Z-direction) electrical conduction between the chip and the substrate electrodes. Subsequently, the device was subjected to performance testing to evaluate its electrical and optical characteristics. Fig. 4 displays the blue Micro-LED and the red and green OLEDs being driven.

Fig. 4. (a) blue Micro-LED (powered at 2.7V) and (b) red and green OLED (powered at 5V).

III. RESULTS AND DISCUSSION

This study conducted photoelectric characteristic testing and data acquisition on individually tested modules of the blue Micro-LED and red/green OLEDs fabricated within the hybrid device, using a multifunctional integrated light-emitting device testing system (D3000-16CH). The testing system consists of a DC power supply unit, a TOPCON integrated spectrometer (SR-3A), and a computer, enabling efficient and accurate measurement of the optoelectronic performance of display devices.

As shown in Fig. 5(a), the I–V characteristic curves of the two blue Micro-LEDs with different mesa sizes exhibit typical PN junction behavior. Both devices have a turn-on voltage of 2.7 V. After turn-on, the current increases exponentially with voltage. Due to the larger active area, the device with a mesa size of 40 $\times$ 90 $\mu$m$^2$ consistently shows a higher current than the 20 $\times$ 70 $\mu$m$^2$ device under the same bias voltage.

As illustrated in Fig. 5(b) and Fig. 5(c), which present the J–V and L–V characteristic curves respectively, under the same voltage after turn-on, the larger-sized Micro-LED experiences current crowding effects. This leads to intense localized heating in the small region beneath the electrodes, forming a local hot spot that results in efficiency degradation. In contrast, the smaller-sized Micro-LED demonstrates better current spreading capability and enhanced heat dissipation. Consequently, the 20 $\times$ 70 $\mu$m$^2$ Micro-LED can sustain a higher current density and deliver greater optical power density. The 40 $\times$ 90 $\mu$m$^2$ Micro-LED, with its larger light-emitting mesa area, achieves a luminous intensity of 3.69 $\times$ 10$^4$ cd/m$^2$ at 4.5 V, which is higher than the 3.08 $\times$ 10$^4$ cd/m$^2$ emitted by the 20 $\times$ 70 $\mu$m$^2$ Micro-LED at the same voltage.

Fig. 5. (a) I–V characteristic curves of 20 $\times$ 70 $\mu$m$^2$ and 40 $\times$ 90 $\mu$m$^2$ blue Micro-LEDs. (b) J–V characteristic curves of 20 $\times$ 70 $\mu$m$^2$ and 40 $\times$ 90 $\mu$m$^2$ blue Micro-LEDs. (c) L–V characteristic curves of 20 $\times$ 70 $\mu$m$^2$ and 40 $\times$ 90 $\mu$m$^2$ blue Micro-LEDs. (d) J–L characteristic curves of 20 $\times$ 70 $\mu$m$^2$ and 40 $\times$ 90 $\mu$m$^2$ blue Micro-LEDs. (e) The M.P.–V (Main peak–Voltage) characteristic curves. (f) Emission spectra of blue Micro-LEDs at different voltages.

As shown in Fig. 5(e), the peak emission wavelength of the blue Micro-LED varies between 455 nm and 449 nm under different voltages. As the voltage increases from 2.5 V to 4.5 V, the peak wavelength of the blue Micro-LED decreases, exhibiting a certain degree of blue shift. This phenomenon primarily occurs because, as the bias voltage rises, the energy of the emitted photons increases, causing the corresponding peak wavelength to shift toward shorter wavelengths.

After testing the two sizes of blue Micro-LEDs, we proceeded to evaluate the optoelectronic performance of the red and green OLEDs.

The I–V characteristic curves of the red and green OLEDs with two different mesa sizes are shown in Fig. 6(a) and Fig. 7(a), respectively. Both I–V curves exhibit typical PN junction behavior, with turn-on voltages of 3 V for both red and green OLEDs—values that are close to the 2.7 V turn-on voltage of the blue Micro-LEDs. This similarity allows them to be controlled using the same driving circuit. After turn-on, the current of both red and green OLEDs increases exponentially with voltage. Due to differences in active area, under the same bias voltage, the device with a mesa size of 70 $\times$ 90 $\mu$m$^2$ consistently shows a higher current than the 50 $\times$ 70 $\mu$m$^2$ device.

Fig. 6. (a) I–V characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ red OLEDs. (b) J–V characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ red OLEDs. (c) L–V characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ red OLEDs. (d) J–L characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ red OLEDs. (e) The M.P.–V characteristic curves. (f) Emission spectra of red OLEDs at different voltages.

By analyzing Fig. 6 and Fig. 7, it can be seen that: the following results were obtained: at 5 V, the 50 $\times$ 70 $\mu$m$^2$ green OLED achieves a luminance of 87.37 cd/m$^2$ (with a current density of 351 mA/cm$^2$), while the 70 $\times$ 90 $\mu$m$^2$ green OLED reaches a luminance of 100.13 cd/m$^2$ (with a current density of 253 mA/cm$^2$). During the same period, the 50 $\times$ 70 $\mu$m$^2$ red OLED exhibits a luminance of 18 cd/m$^2$ (current density: 56 mA/cm$^2$), and the 70 $\times$ 90 $\mu$m$^2$ red OLED reaches 28.1 cd/m$^2$ (current density: 40 mA/cm$^2$). These data indicate that the green OLEDs demonstrate significantly higher luminance and current density than the red OLEDs.

Fig. 7. (a) I–V characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ green OLEDs. (b) J–V characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ green OLEDs. (c) L–V characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ green OLEDs. (d) J–L characteristic curves of 50 $\times$ 70 $\mu$m$^2$ and 70 $\times$ 90 $\mu$m$^2$ green OLEDs. (e) The M.P.–V characteristic curves. (f) Emission spectra of green OLEDs at different voltages.

The smaller-sized OLEDs (50 $\times$ 70 $\mu$m$^2$) exhibit better current spreading capability and stronger heat dissipation performance. Similar to the smaller blue Micro-LEDs, they can sustain higher current densities and deliver greater optical power density. Additionally, as shown in Fig. 6(e) and Fig. 7(e), when the voltage increases from 3 V to 5 V, the peak emission wavelength of the green OLEDs ranges from 512 nm to 514 nm, while the red OLEDs maintain a stable peak wavelength between 608 nm and 611 nm.

Fig. 8 illustrates the evolution of the spectral characteristics of red/green OLEDs and blue Micro-LEDs based on the CIE 1931 chromaticity space. For red/green OLEDs, the variation of chromaticity coordinates with increasing voltage exhibits distinct stage-dependent behavior: at low voltages, dynamic changes in charge balance occur ^[24]—under low-voltage conditions, hole injection dominates, shifting the recombination zone toward the electron transport layer (ETL) side, where red/green guest materials are more efficiently excited (due to their higher excitation efficiency in this region), thereby altering the spectral weight distribution. As the voltage increases, electron injection gradually strengthens, leading to a reconstruction of exciton distribution ^[25]; the recombination zone shifts back toward the center of the emissive layer, and the excitation efficiency of the guest materials adjusts accordingly, causing a rebalancing of the spectral weights. When the voltage enters the high-voltage range, Joule heating (P = I$^2$R) accumulates, raising the device temperature. On one hand, the bandgap of the organic material contracts due to thermal expansion and intensified lattice vibrations, potentially inducing spectral shifts; on the other hand, elevated temperatures enhance Auger recombination and nonradiative recombination processes, reducing luminous efficiency and thereby changing the relative proportion of short-wavelength components in the spectrum. In sharp contrast, the chromaticity coordinates of the blue Micro-LED exhibit a continuously changing trend with increasing voltage. The primary reason lies in the enhanced quantum-confined Stark effect (QCSE) ^[26] or band-filling effect caused by increased injection current—both factors reduce the overlap between electron and hole wavefunctions, ultimately resulting in a significant shift of the peak wavelength.

Fig. 8. CIE 1931 chromaticity coordinates of the blue Micro-LED, red OLED, and green OLED.

From (d) results in Figs. 5, 6, and 7, it can be observed that the emission wavelength fluctuations of red/green OLEDs are all less than 3 nm, whereas during the increase of driving voltage from 2.7 V to 4.5 V, the peak emission wavelength of the blue Micro-LED shifts from 455 nm to 449 nm (a blue shift), indicating a pronounced color deviation. This is mainly because, over the same voltage variation range, the current density of the blue Micro-LED changes by as much as six orders of magnitude (Fig. 5b), while that of the red/green OLEDs changes by only about two orders of magnitude (Figs. 6 and 7(b)). It is worth noting that when the current densities of both the blue Micro-LED and the red/green OLEDs change by two orders of magnitude, their wavelength variations remain within 3 nm, which is consistent with the findings reported in reference ^[27].

Based on the above analysis, the red/green OLEDs and blue Micro-LEDs fabricated in this work demonstrate good spectral stability and color reproducibility. However, for the blue Micro-LED, subsequent implementation of voltage stabilization or color-point compensation strategies in the driving circuit will be necessary to suppress the color deviation caused by large variations in current density.

Meanwhile, we conducted lifetime tests on the fabricated devices. Under ambient conditions of 22 $^\circ$C and 40% relative humidity (RH), red and green OLEDs were operated under a constant voltage of 4 V, with the initial luminance defined as L0. The test results showed that the luminance degradation trends of both types of devices were highly similar and could be well fitted by a stretched exponential decay model ^[28].

According to calculations based on this model, the lifetimes of the red and green OLEDs—defined as the time taken for the luminance to decay to 70% of its initial value (0.7 L0)—were 45 h and 56 h, respectively (Fig. 9). In comparison, the blue Micro-LED, when driven at 4 V under the same environmental conditions and continuously operated for 360 h, still maintained a luminance retention rate above 70% (L360h > 0.70L0), demonstrating significantly superior long-term stability compared to the red and green OLEDs.

Fig. 9. Lifetime of red and green OLEDs.

The limited lifetime of red and green OLEDs is primarily attributed to inadequate encapsulation performance. The currently employed UV resin combined with a glass cover encapsulation exhibits a water vapor transmission rate (WVTR) as high as 21 g/(m$^2\cdot$day), far exceeding the industrial standard for OLED packaging (typically < 10$^{-6}$ g/(m$^2\cdot$day)). High permeation of moisture and oxygen accelerates the oxidation of organic materials and interfacial degradation, which constitutes the key bottleneck restricting OLED lifetime. The existing lifetime data reflect the performance limits under the current encapsulation conditions rather than the intrinsic limits of the materials or device structure itself. In the next step, we will focus on developing Al$_2$O$_3$/HfO$_2$ multilayer barrier film technology based on atomic layer deposition (ALD) ^[29], with the goal of reducing the WVTR to the order of 10$^{-6}$ g/(m$^2\cdot$day), thereby significantly improving the environmental stability and operational lifetime of OLEDs (as confirmed by literature ^[30], ALD has been proven effective in prolonging OLED lifetime).

IV. CONCLUSIONS

This study proposes a novel hybrid device suitable for passive matrix (PM) displays, featuring the successful integration of GaN-based blue Micro-LEDs and red/green OLED subpixels on a single substrate. The experimental results demonstrate that the turn-on voltages of red and green OLEDs with different mesa sizes show minimal variation from that of the blue Micro-LED, indicating that all three types of devices can be activated using the same driving voltage. Notably, under a driving voltage of 4.5 V, the blue Micro-LED achieves a luminance of up to 10$^4$ cd/m$^2$, significantly outperforming the red and green OLED devices.

To meet the requirements of subsequent full-color display applications, we will address the brightness mismatch between the blue Micro-LEDs and red/green OLEDs by adjusting the driving duty cycles of the RGB subpixels, or by appropriately increasing the emission area of the red/green OLEDs while correspondingly reducing the area of the blue Micro-LEDs, based on their distinct luminescence characteristics. Meanwhile, future research will focus on optimizing material systems, exploring resonant cavity structures, and enhancing process stability, in order to bring the luminance of red/green OLEDs closer to that of the blue Micro-LEDs, thereby achieving optimal display performance.

This study provides important theoretical foundations and practical guidance for the development of high-performance driving and control strategies for RGB full-color displays. Based on the existing experimental data, further improvements in device structure can be pursued in the future to enhance display resolution, ultimately enabling the practical realization of full-color displays using hybrid blue Micro-LED and red/green OLED devices. This approach opens up a new technological pathway for full-color display technology.