Combining blue micro‐light‐emitting diodes (LEDs) with color conversion layers (CCLs) is a promising approach to develop efficient full‐color displays. However, no such practical display is reported so far potentially because of two major challenges, i.e., rarely available color conversion materials and severe crosstalk effect among adjacent pixels due to the thick sapphire substrates of LED chips. Here, a full‐color micro‐LED display prototype by combining rationally designed blue micro‐LEDs backlight with CsPbBr3 perovskite and CdSe QDs as green and red CCLs, respectively, is presented. The color gamut of the fabricated display can reach as high as 129% of the National Television Standards Committee (NTSC). Notably, the color gamut can still reach 126% NTSC even when only green light is converted through perovskite CCL while the other two colors are achieved from conventional micro‐LEDs. This is the first demonstration on employing perovskite materials as CCL in full‐color micro‐LEDs display.

In this letter, the hysteresis mechanism of organic thin-film transistors (OTFTs) with polyvinyl alcohol (PVA) as gate dielectric is studied. By examining OTFTs with a blocking polymer layer between gate and PVA or between channel and PVA, we confirm that the origin of the hysteresis is caused by the holes injected from the gate and/or from the channel and trapped in the interface of pentacene/PVA and the PVA bulk. A method is proposed to reduce the hysteresis. As a result, a pentacene OTFT with free-hysteresis and high mobility of 1.8 cm2/Vs is achieved by a triple-layer polymer dielectric at low-operating voltages.

Photoalignment is a simple technique for the manipulation of molecular orientations, which has been widely used in liquid crystal displays. Here, we propose a novel photoalignment method, in which an azobenzene dye thin film is deposited by thermal evaporation and in situ exposed to linearly polarized light simultaneously. We obtain polarizers with a dichroic ratio of up to 62, which is the highest value ever realized by a photoalignment method. Moreover, the polarizing thin film has a thickness of just 200 nm, compatible with flexible substrates, making it perfect for use as a dichroic polarizer in ultrathin and flexible displays.