Dipole Field-Driven Organic–Inorganic Heterojunction for Highly Sensitive Ultraviolet Photodetector

作者：Minghao Li, Cheng Wu, Mengshan Chen, Tianfeng Weng, Xuan Yu, Kun Lin, Yu Cao, Xiaoming Yu, Zhenhua Li, Qian Qiao, Hai Zhang, Yingtang Zhou · 发表于：ACS Applied Materials & Interfaces · 年份：2024 · DOI：10.1021/acsami.3c16985 · 被引用次数：23 · 研究领域：Gas Sensing Nanomaterials and Sensors、Ga2O3 and related materials、ZnO doping and properties

Developing high-performance organic–inorganic ultraviolet (UV) photodetectors (PDs) has attracted considerable attention. However, this development has been hindered due to poor directional charge-transfer ratios in transport layers, excessive costs, and an ambiguous underlying mechanism. To tackle these challenges, we constructed a heterojunction of economic Mg-doped ZnO (MgZnO) nanorods and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) [PEDOT:PSS (P:P)] that utilizes dipole field-driven spontaneous polarization to enhance photogenerated charge kinetics. As a result, the proposed heterojunction has an improved noise equivalent power of 3.16 × 10 –11 W Hz –1/2 ), a normalized detection rate ( D *) of 8.96 × 10 9 jones, and external quantum efficiency comparable to other ZnO-based devices. Notably, the prepared PDs showed a photocurrent of 4.8 × 10 –3 μA under a faint UV light having an intensity of 1 × 10 –5 W cm –2, exceeding the performance of the most state-of-the-art ZnO-based UV sensors. The introduction of Mg into ZnO is responsible for the high performance, as it causes a lattice mismatch and distortion of the Mg-doped ZnO unit cell. It results in improved dipole movement and the creation of a dipole field, accelerating the directional electron-transfer process. Using a dipole field to manipulate the migration and transport of photogenerated carriers represents a promising approach for achieving outstanding performance in UV PDs.