Strong light-matter interaction and antireflection functionality of f-TiO2/GaN heterostructure broadband photodetector

Abstract

Recent research focusing on broadband photodetectors offers a diverse range of applications like civilian, military, medical, etc. However, the available broadband photodetectors unable to retain high state-of-art performance parameters when operating at wide bandwidth. Herein, we report a broadband photodetector based on fibrils like TiO2 (f−TiO2) and GaN heterostructure. The TiO2 thin film has a high density of photo-generated charge carriers due to its great light absorption, antireflective, and highly oxidizing properties. These features of TiO2 enable a considerable increase in photocurrent for f−TiO2/GaN heterostructures compared to bare GaN, which provided a massive gain in the figure-of-merit performance metrics of f−TiO2/GaN-based devices. The fabricated f−TiO2/GaN device exhibits excellent optoelectronic characteristics, such as high responsivity (3.4 × 104 AW−1), outstanding external quantum efficiency (1.2 × 107 %), and detectivity (2.4 × 1012 Jones) under a weak optical signal of 90 nW. The design heterostructure-based photodetector also noticeably responds to illumination between the wavelengths of 250 nm and 780 nm. Additionally, TiO2 exhibits antimicrobial surface behavior, making it the best choice for pervasive biological and medical applications. Thus, TiO2/GaN heterostructure-based device like environmental screening, agriculture, medicine, and biodefense have proven their immense versatility in next-generation sequencing technology, medical science, cutting-edge crops, and creating interactive environments.