A Comprehensive Review of Semiconductor Ultraviolet Photodetectors: From Thin Film to One-Dimensional Nanostructures

Abstract

Ultraviolet (UV) photodetectors have drawn extensive attention owing to their applications in industrial, environmental and even biological fields. Compared to UV-enhanced Si photodetectors, a new generation of wide bandgap semiconductors, such as (Al, In) GaN, diamond, and SiC, have the advantages of high responsivity, high thermal stability, robust radiation hardness and high response speed. On the other hand, one-dimensional (1D) nanostructure semiconductors with a wide bandgap, such as β-Ga2O3, GaN, ZnO, or other metal-oxide nanostructures, also show their potential for high-efficiency UV photodetection. In some cases such as flame detection, high-temperature thermally stable detectors with high performance are required. This article provides a comprehensive review on the state-of-the-art research activities in the UV photodetection field, including not only semiconductor thin films, but also 1D nanostructured materials, which are attracting more and more attention in the detection field. A special focus is given on the thermal stability of the developed devices, which is one of the key characteristics for the real applications.

A self-powered high-performance graphene/silicon ultraviolet photodetector with ultra-shallow junction: breaking the limit of silicon?

“…For our Gr/Si UV photodetector, J ph and J dark are 12 μA cm −2 and 0.1 nA cm −2 (under vacuum) at zero-bias (selfpowered) mode, respectively, leading to R I = 0.12 A W −1 at 365 nm UV light. The responsivity and dark current density are comparable to the-state-of-art compound semiconductor Schottky photodetectors such as GaN (R I~0 .10 A W −1 , J dark~5 00 nA cm −2 ) and SiC (R I~0 .03 A W −1 , J dark~0 .25 nA cm −2 ) (see refs [1][2][3][4][5][6][7][8]. The dark current density of our Gr/Si photodetector is smaller than the typical metal-semiconductor Schottky photodetectors owing to the finite density of states of 2D materials and smaller electronic injection ratio from silicon to graphene, as compared with the traditional metal-semiconductor contact.…”

“…Ultraviolet (UV) photodetectors could find a wide range of applications, [1][2][3][4][5][6][7][8] such as environmental monitoring, 3 biological and chemical analysis, 4 flame detection, 5 astronomical studies, 8 internet-of-things sensors, 9 and missile detection. 10 Recently, wide band-gap (WBG) semiconductors (SiC, 11 GaN, 12 ZnO, 13 TiO X , 14 etc.)…”

A study of hydrothermally grown ZnO nanorod-based metal-semiconductor-metal UV detectors on glass substrates

“…Zinc oxide (ZnO) is a promising semiconductor material for ultraviolet (UV) and blue light detection-based applications such as optically pumped lasers, 1 photodetectors (PDs), 2,3 and light-emitting diodes. 4 Remarkably, ZnO possesses a wide bandgap of approximately 3.37 eV and a large exciton binding energy of 60 meV.…”

β-Ga2O3 solar-blind deep-ultraviolet photodetector based on a four-terminal structure with or without Zener diodes

“…6 Nevertheless, it is also sensitive to the infrared, visible and near-UV radiations due to the small bandgap (E g ) of Si (1.1 eV), 7,8 and accordingly expensive and cumbersome Woods optical filters have to be employed in solar-blind DUV detection system. 1,2 In this case, photodetectors based on wide-bandgap semiconductors are regarded as better alternatives. Among them, monoclinic Ga 2 O 3 ( β-Ga 2 O 3 ) with an intrinsic E g of 4.9 eV is naturally suitable for solar-blind DUV detection, 9,10 and so can avoid the alloying process in material growth for AlGaN 11,12 and ZnMgO.…”

“…1,2 Accordingly, this kind of photodetectors can accurately respond to a very weak signal even under sun or room illumination, providing an incomparable advantage especially for applications such as ozone-hole monitoring, flame detection and missile early warning. [3][4][5] At present, Si-based photodiode is the most commonly used in commercial applications due to its high compatibility with the mature silicon process.…”