https://scholar.dgist.ac.kr/handle/20.500.11750/60493 2026-08-10T13:43:36Z https://scholar.dgist.ac.kr/handle/20.500.11750/60596 Title: Self-Powered ZnSnN2/GaN Photodiodes via Fine Stoichiometry Control and Photon Trapping Micropatterned Heterojunctions Under Low-Light Irradiation Author(s): Kim, Jeong Hyeon; Hwang, Ju Chan; Yoon, Soon Joo; Lee, Yoon Kyueng; Lee, Taehun; Min, Jungwook; Kim, Jongmin; Park, Kwangwook; Lee, Haneol Abstract: Recent advances in energy-autonomous optoelectronic devices have attracted significant attention for next-generation applications. However, developing compound semiconductor-based self-powered photodiodes remains challenging due to difficulties in precise band alignment control and limited light absorption efficiency. Here, we demonstrate a self-powered photodiode based on a ZnSnN2 (ZTN)/GaN heterostructure, featuring an enhanced built-in electric field via fine stoichiometry control and light-trapping micropatterned heterojunctions. Through stoichiometric engineering, the ZTN thin-film exhibited an optimized carrier concentration of 3.34 & times; 1019 cm-3 and a bandgap of 2.27 eV. Consequently, the heterostructure achieved a strong built-in electric field of 88 kV cm-1 due to the degenerate n-type properties of ZTN. To further reinforce light absorption, we introduced periodic microhole patterns, and the resulting micropatterned heterojunction exhibited a substantial carrier lifetime of 6.2 ns, representing a 1.8-fold enhancement over the thin-film structure. Finally, the device demonstrated robust power-saving operation under zero-bias conditions, successfully driving a commercial temperature/humidity sensor. Moreover, the device exhibited a linear dynamic range of 15.1 dB and stable linearity (theta approximate to 0.27) even under low-light conditions, ensuring reliable operation in varying illumination environments. These results suggest that our dual approach of stoichiometric and structural engineering offers a scalable pathway for next-generation self-powered optoelectronic systems. 2026-06-30T15:00:00Z