Flexible Ultraviolet Photodetectors Based on One-Dimensional Gallium-Doped Zinc Oxide Nanostructures

Abstract

Wide band gap semiconductors such as ZnO are characterized by unique optoelectronic properties, which have led to numerous applications in the field of sensors and optoelectronics. These components are commonly fabricated on rigid substrates. However, the same synthesis method cannot be used to fabricate these components on flexible substrates. In this work, we present a method to fabricate metal−semiconductor−metal ultraviolet photodetectors with ZnO nanorods on flexible substrates. It is observed that the overall characteristics of the fabricated ZnO nanorod photodetector are greatly enhanced by doping with gallium (Ga). The nanorods are grown on a flexible substrate (poly(ethylene 2,6-naphthalate)) at a low temperature of 80 °C. The performance of Ga-doped ZnO nanorods (GZO) shows a significant improvement in electrical measurements compared to pure ZnO nanorods. The photocurrent-to-dark current ratios of both ZnO and GZO nanorod-based photodetectors are approximately 8.5 and 570.2 under a 1 V bias, respectively. The dark current and photocurrent are substantially improved by the addition of the Ga dopant. Transient response measurements indicated that the GZO nanorod photodetectors are stable and reproducible, and no change in the current−voltage characteristics is noted after multiple bending cycles. These results indicate that Ga-doping can improve the ZnO nanorod optical and electric characteristics; this proposed method is useful for device fabrication on low-melting-point substrates to produce flexible costeffective devices.

Fabrication of graphene–ZnO heterostructure-based flexible and thin platform-based UV detector

“…The responsivity and detectivity of the device are seen to be higher than the exiting graphene/ZnO-based devices as well as other ZnO-based p-n, MSM and Schottky junctions. The device is expected to exhibit similar responses even when it is bent [37,38]. It is clear from the results that the fabricated device outperforms the existing devices and thereby becomes a potential competitor for the existing flexible detectors that are expected to dominate the future's Si photonic and optoelectronic market.…”

Optical and Electrical Properties of Mn-doped and Mn–Al co-doped ZnO Thin Films Annealed at Different Temperatures for Photosensor Applications

“…However, ZnO films have high electrical resistance, which hinders their practical application. (4)(5)(6)(7)(8)(9) Accordingly, the problem of improving the electrical performance of ZnO thin films through doping with metallic elements such as Al, Ga, Ag, Ti, Zr, and Mo has attracted significant attention in recent years. (10)(11)(12)(13)(14)(15) In such methods, the doped atoms substitute for the Zn atoms in the ZnO crystal structure and produce free electrons in the conduction band, which lower the electrical resistivity.…”

Synthesis of encapsulated ZnO nanowires provide low impedance alternatives for microelectrodes

“…A more recent introduction to nanowire technology has been the introduction of vertical zinc oxide nanowires (ZnO NWs), an n-type semiconductor, commonly used in light-emitting diodes (LEDs) [ 50 , 51 ], solar cells [ 52 – 56 ], biosensors [ 57 – 59 ], piezoelectric devices [ 60 – 62 ] and sensing applications [ 63 , 64 ] due to their excellent electronic and optoelectronic properties. Another favourable property of ZnO NWs is that they can be grown via hydrothermal synthesis at temperatures below 100°C, which is both a low cost and scalable fabrication method [ 65 ].…”