As display technologies evolve toward full-screen, transparent, near-eye, and smart cockpit applications, the ability of panels to actively manage incoming and outgoing light has become a new technological frontier. Electrochromic (EC) devices, with their low-power bistability, high transmittance modulation, and color design freedom, are emerging as ideal functional layers integrated into displays for dynamic light control. Starting from our main research on patterned EC active privacy technology, this paper reviews the varied needs of the display industry for EC devices and materials.
First, we propose an EC privacy display module. Patterned EC devices are placed in the pixel projection gaps (top view, Fig. 1a) and on the encapsulation layer (cross-section, Fig. 1b), enabling viewing angle control by switching their tinted state. We have elaborated on the stringent requirements of the switchable privacy display for EC devices, including sub-millisecond response time, strong light-blocking capability, neutral black color, long cycle life, and flexible ultra-thin packaging. These are essential for integrating EC into panels. Then, we explore five other applications that depend heavily on EC advances: (1) Under-display camera optical shutter, requiring fast, clear-to-dark switching in a tiny area with excellent optical uniformity and electric field control. (2) Dynamic dark background for transparent displays, demanding the ability that can instantly change between transparency and black. (3) Ambient light adaptive layer for AR glasses, utilizing non-polarization and low-power grayscale modulation to ensure clear overlay of virtual and real information outdoors. (4) Hidden displays and dimmable surfaces for smart cockpits, emphasizing automotive-grade wide-temperature reliability, multi-color interior integration, and zone control. (5) Low-power reflective color e-paper, pursuing full-color, high-saturation static image maintenance with zero power.
Looking across these applications, we find common requirements: micro/nano-scale patterning and addressing, flat neutral absorption across the visible spectrum, millisecond to sub-second ion transport, durability over hundreds of thousands of cycles, and seamless integration with flexible TFT backplanes.

Electrochromism; Display panel; Active privacy; Patterned device; Smart light management