Controllable Growth of Wafer-Scale Te1-xSex Thin Films Based on Selenium Phase Change-Induced Strategy for Single-Pixel Imaging.

Abstract

Recently, Te_1-xSe_x films have shown significant potential for infrared detection. However, the conventional deposition process of Te_1-xSe_x films typically requires a cooled substrate, which results in the formation of poorly crystallized materials. Achieving controlled synthesis of large-area Te_1-xSe_x films remains a major challenge. Herein, two-inch Te_1-xSe_x films is successfully prepared using a low-pressure chemical vapor deposition technique based on a selenium phase transition-induced strategy. The chemical compositions of Te_1-xSe_x (x ranging from 0 to 1) films can be precisely controlled by adjusting the molar ratio of Te and Se powders. The phase change of amorphous Se at elevated temperatures generates additional dangling bonds on its surface, which facilitates the incorporation of Te atoms into Se chains forming Te_1-xSe_x alloys. COMSOL simulations reveal that maintaining uniform concentration and temperature during the growth process is essential for the formation of Te_1-xSe_x films. Importantly, the Te_0.4Se_0.6 film detector realizes high-performance near-infrared single-pixel imaging with a resolution of 128 × 128 pixels. This work has fabricated wafer-scale Te_1-xSe_x alloy thin films, which exhibit excellent properties, providing important experimental and theoretical support for exploring the applications in the fields of electronics, photonics, and optoelectronics.