Tunable Ultraviolet Photoresponse in Solution-Processed p–n Junction Photodiodes Based on Transition-Metal Oxides

Abstract

Solution-processed p-n heterojunction photodiodes have been fabricated based on transition-metal oxides in which NiO and ternary Zn(1-x)Mg(x)O (x = 0-0.1) have been employed as p-type and n-type semiconductors, respectively. Composition-related structural, electrical, and optical properties are also investigated for all the films. It has been observed that the bandgap of Zn(1-x)Mg(x)O films can be tuned between 3.24 and 3.49 eV by increasing Mg content. The fabricated highly visible-blind p-n junction photodiodes show an excellent rectification ratio along with good photoresponse and quantum efficiency under ultraviolet (UV) illumination. With an applied reverse bias of 1 V and depending on the value of x, the maximum responsivity of the devices varies between 0.22 and 0.4 A/W and the detectivity varies between 0.17 × 10(12) and 2.2 × 10(12) cm (Hz)(1/2)/W. The photodetectors show an excellent UV-to-visible rejection ratio. Compositional nonuniformity has been observed locally in the alloyed films with x = 0.1, which is manifested in photoresponse and X-ray analysis data. This paper demonstrates simple solution-processed, low cost, band tunable photodiodes with excellent figures of merit operated under low bias.

Recent Progress of Heterojunction Ultraviolet Photodetectors: Materials, Integrations, and Applications

“…A solution‐processed p‐n heterojunction photodiode is fabricated based on NiO and ternary Zn 1− x Mg x O ( x = 0–0.1). The fabricated visible‐blind p‐n junction photodetector demonstrates an excellent rectification ratio and displays good UV responsivity and high quantum efficiency 118 3) Metal chalcogenide : Semiconducting metal chalcogenides mainly include group IIIA, IVA, and VA chalcogenides that have demonstrated their numerous intriguing characteristics and tremendous potential in photoelectric detection 119,120.…”

UV-assisted room-temperature chemiresistive NO2 sensor based on TiO2 thin film

“…Solid-state semiconductor oxides have drawn continuous attention for the last few decades, as they promise miniature and low-cost sensors with capability of detecting numerous gas species and many other optoelectronic applications [5-8]. Among the studied oxide semiconductors, titanium dioxide (TiO 2 ) stands out owing to its extraordinary chemical stability, resistance to harsh atmospheric conditions [9], and low production cost.…”

Self-powered p-NiO/n-ZnO heterojunction ultraviolet photodetectors fabricated on plastic substrates

“…8–10, 12, 14 Despite the advantage of simple fabrication process as well as low stray capacitance, high internal gain of ZnO based Schottky and metal-semiconductor-metal PDs, p-n junction structure appears to be more promising due to its stability, low or zero bias currents, high impedance, lower applied filed and faster response. 8, 14, 15 p-type ZnO is an obvious choice to make p-n homojunction with intrinsic n-type ZnO but p-type doping is very difficult. Among the variety of p-type materials that have been employed to form p-n junction with ZnO, p-NiO stands out due to its band alignment with ZnO and its alloys in UV PD applications.…”

“…Among the variety of p-type materials that have been employed to form p-n junction with ZnO, p-NiO stands out due to its band alignment with ZnO and its alloys in UV PD applications. 15, 17, 18 Although excellent figures of merits have been achieved in NiO/ZnO PDs, most of the devices have been fabricated on rigid substrates using high processing temperature without any self-powered behavior 16, 17 which can limit their application on plastic substrates. On the other hand, some devices have shown very slow temporal response 18 that may not be suitable for high-speed device applications.…”