Pyro-Phototronic Effect Enhanced Pyramid Structured p-Si/n-ZnO Nanowires Heterojunction Photodetector

Mingyan Xue; Wenbo Peng; Xuefeng Tang; Yahui Cai; Fangpei Li; Yongning He

doi:10.1021/acsami.2c18011

Pyro-Phototronic Effect Enhanced Pyramid Structured p-Si/n-ZnO Nanowires Heterojunction Photodetector

ACS Appl Mater Interfaces. 2023 Jan 25;15(3):4677-4689. doi: 10.1021/acsami.2c18011. Epub 2023 Jan 10.

Authors

Mingyan Xue^{1

2}, Wenbo Peng^{1

2}, Xuefeng Tang^{1

2}, Yahui Cai^{1

2}, Fangpei Li³, Yongning He^{1

2}

Affiliations

¹ School of Microelectronics, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
² The Key Lab of Micro-Nano Electronics and System Integration of Xi'an City, Xi'an, Shaanxi 710049, China.
³ State Key Laboratory of Solidification Processing, Key Laboratory of Radiation Detection Materials and Devices, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.

PMID: 36625530
DOI: 10.1021/acsami.2c18011

Abstract

The emergence of nanomaterials has brought about the development of miniature photodetectors into a new stage, and ZnO nanomaterials are currently one of the most popular research objects. Here, the performance of a photodetector consisting of micropyramid structured p-Si/n-ZnO NWs heterojunction constructed by an anisotropic chemical etching and hydrothermal method is optimized by using the pyro-phototronic effect, and the photoresponses of the device to 405 and 648 nm lasers are investigated. The results show that, with the introduction of pyro-phototronic effect, the photoresponsivity R_pyro increases to 208 times that of R_photo when the wavelength is 405 nm and the optical power density is 0.0693 mW/cm². Moreover, with the increase of the chopper frequency, the photocurrent increases by more than 3 times, and the photoresponsivity is also increased by a factor of 4.5, making it possible to detect ultrafast pulsed light. In addition, in order to increase the current collection efficiency, a thin film Al layer was deposited as the back electrode on the basis of the device, and the photocurrent and photoresponsivity are significantly improved. Finally, the coupling between the pyro-phototronic effect and the piezo-phototronic effect is analyzed by applying compressive strain to the photodetector. When the compressive strain is -1.02%, the photocurrent decreases by 31.4% and the photoresponsivity decreases by 27.9% due to the opposite direction between laser illumination induced pyroelectric polarization charges and compressive strain induced piezoelectric polarization charges. This work not only demonstrates the great potential of pyro-phototronic effect in enhancing the silicon-based heterojunction photodetectors for high-performance photodetection and ultrafast pulsed light detection but also provides assistance for a better understanding of the coupling mechanism between pyro-phototronic and piezo-phototronic effects.

Keywords: ZnO nanowires; photodetector; piezo-phototronic effect; pyramid structured Si; pyro-phototronic effect.