Transparent Co3O4/ZnO photovoltaic broadband photodetector. (October 2020)

• Record Type: Journal Article
• Authors: Rana, Amit Kumar; Patel, Malkeshkumar; Nguyen, Thanh Tai; Yun, Ju-Hyung; Kim, Joondong
• Is Part Of: Materials science in semiconductor processing. Volume 117(2020)
• Publication Date: 2020-10
• Subjects: Spinel-Co3O4/ZnO -- Transparent -- Photovoltaic -- Photodetector -- Metal oxide; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.105192
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Based on the requirements of transparent optoelectronic devices, herein we report a highly transparent broadband photodetector, which is based on spinel structured p-Co3 O4 and n-ZnO heterojunction. The XRD and XPS analysis confirmed the wurtzite ZnO phase along with the formation of spinel structured Co3 O4 . The structural property shows the good crystalline properties of the heterostructure thin films. The optical properties reveal the dual absorption states of Co3 O4 corresponding to the Co 2+ state (Eg = 1.93 eV) and Co 3+ state (Eg = 1.42 eV) along with wide band gap ZnO (3.2 eV). Moreover, the photodetector shows an impressive transmittance of ~76% in the visible window. Further, the photoelectrical performance shows the prominent photovoltaic effect (self-powered operation) with a significant photosensitivity of 4.57 × 10 4 . Moreover, the device is also capable of absorbing broad wavelengths from ultraviolet (UV) to infrared (IR) range. Importantly the device exhibits a fast response speed of 81.7 μs and a decay time of 178.8 μs which are found to be the fastest speed reported for transparent metal oxide-based p-n heterojunction devices under white light and self-powered mode. This work thus provides a comprehensive way of utilizing the robust metal oxide layers for developing a fast-high performing transparent self-powered device. The dual bandgap configuration of spinel Co3 O4 demonstrates the wide range photo-responses, which is a promising feature for broadband transparent photodetectors and enhanced transparent photovoltaics.