Efficient Charge Separation in Polypyrrole/GaN‐Nanorod‐Based Hybrid Heterojunctions for High‐Performance Self‐Powered UV Photodetection. Issue 12 (26th January 2021)

• Record Type: Journal Article
• Authors: Pasupuleti, Kedhareswara Sairam; Reddeppa, Maddaka; Park, Byung-Guon; Oh, Jae-Eung; Kim, Song-Gang; Kim, Moon-Deock
• Is Part Of: Physica status solidi. Volume 15:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-26
• Subjects: GaN nanorods -- hybrid structures -- polypyrrole -- UV photodetectors; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202000518
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : The ozonosphere is infiltrated by UV‐A rays ( λ = 320–400 nm) that reach the Earth's atmosphere, posing serious health problems such as premature aging and skin cancer. Owing to the importance of UV‐A ray detection, highly detective, novel, and high‐speed UV‐A photodetectors have recently attracted considerable attention. The integration of organic and inorganic hybrid structures yields highly attractive optoelectronic properties that make them attractive candidates for high‐performance self‐powered UV‐A photodetectors. Herein, the integration of conductive polypyrrole (Ppy) and GaN nanorods for high‐performance self‐powered UV‐A photodetectors is demonstrated. The device exhibits superior photoresponse properties such as detectivity, responsivity, and external quantum efficiency values as 5.0 × 10 12 Jones, 102 A W −1, and 29.8 × 10 3 %, respectively, at a power density of 1.32 mW cm −2 ( λ = 382 nm) and zero bias, which are relatively higher than those of pristine GaN nanorods. Furthermore, the device exhibits good stability and reproducibility with fast rising (350 ms) and falling (410 ms) times. The high photoresponse is attributed to the large built‐in potential formed at the interface junction of the Ppy and the GaN nanorods. Furthermore, the mechanism behind the high photoresponse is investigated using an X‐ray photoelectron spectroscopy (XPS) analysis and energy band theory. Abstract : Organic–inorganic‐based hybrid heterostructure devices are attractive candidates for high‐performance self‐powered UV‐A photodetector applications. The design and fabrication of polymer‐functionalized GaN‐nanorod hybrid heterostructures for UV photodetection is reported. Reduction of surface states, high optical absorption, and excellent charge generation and charge transport in the hybrid devices are state‐of‐art for outstanding optoelectrical properties.