Abstract
In this work, a GaN-based UV photodetector with an asymmetric electrode structure was fabricated by atomic layer deposition (ALD) of TiN layers. The thickness of the TiN can be monitored in situ by a quartz crystal microbalance (QCM) and precisely controlled through the modulation of deposition cycles. During the ALD process, periodic variation in the QCM frequency was observed and correlated to the physical adsorption, chemical bonding, and the excessive precursor exhaust, which included tetrakis(dimethylamino)titanium (TDMAT) and N sources. The asymmetric TiN/GaN/TiN photodetector showed excellent photosensing performance, with a UV-visible rejection ratio of 173, a responsivity of 4.25 A/W, a detectivity of 1.1×1013 Jones, and fast response speeds (a rise time of 69 μs and a decay time of 560 μs). Moreover, the device exhibits high stability, with an attenuation of only approximately 0.5% after 360 nm light irradiation for 157 min. This result indicates the potential of TiN as a transparent contact electrode for GaN-based optoelectronic devices.
© 2022 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Zhiying Zhou, Fengzhou Zhao, Cheng Wang, Xiaoxuan Li, Shunli He, Dan Tian, Dengying Zhang, and Lichun Zhang
Opt. Express 30(16) 29749-29759 (2022)
Yang Liu, Huaqing Yu, Qingdong Zeng, and Qingyu Ruan
Opt. Lett. 48(23) 6296-6299 (2023)
Ruilin Meng, Xiaoli Ji, Zheng Lou, Jiankun Yang, Yonghui Zhang, Zihui Zhang, Wengang Bi, Junxi Wang, and Tongbo Wei
Opt. Lett. 44(9) 2197-2200 (2019)