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Review
. 2020 Jun 18:9:105.
doi: 10.1038/s41377-020-0341-9. eCollection 2020.

Mini-LED, Micro-LED and OLED displays: present status and future perspectives

Yuge Huang #  1 , En-Lin Hsiang #  1 , Ming-Yang Deng #  1 , Shin-Tson Wu  1
Affiliations
Review

Mini-LED, Micro-LED and OLED displays: present status and future perspectives

Yuge Huang et al. Light Sci Appl. .

Abstract

Presently, liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays are two dominant flat panel display technologies. Recently, inorganic mini-LEDs (mLEDs) and micro-LEDs (μLEDs) have emerged by significantly enhancing the dynamic range of LCDs or as sunlight readable emissive displays. "mLED, OLED, or μLED: who wins?" is a heated debatable question. In this review, we conduct a comprehensive analysis on the material properties, device structures, and performance of mLED/μLED/OLED emissive displays and mLED backlit LCDs. We evaluate the power consumption and ambient contrast ratio of each display in depth and systematically compare the motion picture response time, dynamic range, and adaptability to flexible/transparent displays. The pros and cons of mLED, OLED, and μLED displays are analysed, and their future perspectives are discussed.

Keywords: Displays; Inorganic LEDs.

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Conflict of interest statement

Conflict of interestThe authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1. Display system configurations.
a RGB-chip mLED/μLED/OLED emissive displays. b CC mLED/μLED/OLED emissive displays. c mini-LED backlit LCDs
Fig. 2
Fig. 2. Pulse amplitude modulation LED driving schematics.
a 2T1C active matrix and b basic passive matrix circuitries
Fig. 3
Fig. 3. Operating spots of OLED displays and μLED displays.
VDS: the TFT drain-to-source voltage. VF, OLED: the OLED forward voltage. VF, μLED: the μLED forward voltage
Fig. 4
Fig. 4. Illustration of VDD voltage drop.
a System schematic of an AM panel. b Voltage drop on a VDD line
Fig. 5
Fig. 5. OLEDs and μLED characteristics.
a EQEchip as a function of chip luminance. The RGB dashed lines are for RGB OLEDs. The RGB solid lines are for RGB mLEDs. b Current-dependent EQEchip (solid lines) and normalized EQEchip/VF (dashed lines) of RGB mLEDs, as denoted by RGB colours, respectively
Fig. 6
Fig. 6. Chip size-dependent LED power consumption with different display technologies.
a 50-μm pitch smartphone under 1500-lux overcast daylight for ACR=40:1. b 90-μm pitch notebook under 500-lux office light for ACR=100:1. c 375-μm pitch (65-inch 4K) TV under 150-lux living room ambient for ACR = 1000:1
Fig. 7
Fig. 7. Pixel response time-dependent MPRT at different frame rates.
fps: frames per second
Fig. 8
Fig. 8
Chromaticity (x, y) of mLED/μLED/OLED displays in comparison with Rec. 2020
Fig. 9
Fig. 9
Chip size versus the on-axis power efficacy (ηW) for the four specified display technologies
See this image and copyright information in PMC

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