A p-silicon nanowire/n-ZnO thin film heterojunction diode prepared by thermal evaporation

Abstract

This paper represents the electrical and optical characteristics of a SiNW/ZnO heterojunction diode and subsequent studies on the photodetection properties of the diode in the ultraviolet (UV) wavelength region. In this work, silicon nanowire arrays were prepared on p-type (100)-oriented Si substrate by an electroless metal deposition and etching method with the help of ultrasonication. After that, catalyst-free deposition of zinc oxide (ZnO) nanowires on a silicon nanowire (SiNW) array substrate was done by utilizing a simple and cost-effective thermal evaporation technique without using a buffer layer. The SEM and XRD techniques are used to show the quality of the as-grown ZnO nanowire film. The junction properties of the diode are evaluated by measuring current-voltage and capacitance-voltage characteristics. The diode has a well-defined rectifying behavior with a rectification ratio of 190 at ˙2 V, turn-on voltage of 0.5 V, and barrier height is 0.727 eV at room temperature under dark conditions. The photodetection parameters of the diode are investigated in the bias voltage range of ˙2 V. The diode shows responsivity of 0.8 A/W at a bias voltage of 2 V under UV illumination (wavelength D 365 nm). The characteristics of the device indicate that it can be used for UV detection applications in nano-optoelectronic and photonic devices.

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

“…The responsivity of the fabricated graphene/ZnO based photodetector was found to be 0.49 A W -1 . The responsivity in the existing devices that are reported recently lies in the range of 0.1 to 0.35 A W -1 [14,[31][32][33][34][35][36]. The enhanced value of responsivity attained in the fabricated device makes it promising towards practical applications where high responsivity becomes mandatory.…”

Substrate Temperature Effect on the Spectrum Emission in Superconductor Heterostructure BiPbSrCaCuZnO

“…photo excitation from an impurity or interface state) and free electron hole pairs (i.e. electron transition of the valence band into the conduction band) [4,5]. The free carries, generated by these processes at the interface or with diffusion length, in the two semiconductors forming a heterojunction, give rise to photo currents at the heterojunction [4].…”

“…When these minority carriers recombine with majority carriers in the respective regions, they lose energy and radiate photons as visible lightemitting. Diodes are widely used for digital displays in clocks and electronic device [5,6].…”

High performance GZO/p-Si heterojunction diodes fabricated by reactive co-sputtering of Zn and GaAs through the control of GZO layer thickness

“…26 The n-ZnO/p-Si heterojunction diodes are specially attractive, owing to the availability and quality of crystalline silicon, as well as the possibility of hybrid integration of ZnO based devices with high density silicon technology. As a result, fabrication of n-ZnO/p-Si heterojunction diodes have been attempted by various deposition processes, such as thermal evaporation, 27,28 chemical bath deposition 29 magnetron sputtering 30,31 pulsed laser deposition 32,33 and chemical vapour deposition, 34 albeit with moderate performance, resulting in diode ideality factors, usually in the range of 2-10. [35][36][37] Owing to closeness of the ionic radii of Ga and Zn, Ga-doped ZnO (GZO) lms can be obtained with minimal defects and strain 38,39 and hence, are attractive for controlled doping of ZnO and fabrication of ZnO-based devices.…”

“…The immense technological advantages, such as, low temperature operation, high deposition rates, uniformity and scalability, have driven the application of RF sputtering of a ZnO-Ga 2 O 3 ceramic target for the routine deposition of GZO lms. 2,3,6,34,35 Being particularly suitable for device fabrication on exible substrates, RF sputtering of a ZnO-Ga 2 O 3 ceramic target has also been employed to fabricate ZnO-based heterojunction diodes. [40][41][42] Interestingly, the use of reactive co-sputtering of Zn and Ga targets has been rather scarce, possibly due to the melting of Ga near room temperature, although there have been some attempts to reactively sputter a Zn-Ga alloy target in Ar-O 2 atmosphere for depositing GZO lms.…”