Self-powered ultraviolet photodetector based on an n-ZnO:Ga microwire/p-Si heterojunction with the performance enhanced by a pyro-phototronic effect

Abstract

In the present study, a heterojunction made of an individual ZnO microwire via Ga incorporation (ZnO:Ga MW) with a p-Si substrate was constructed to develop a self-powered ultraviolet photodetector. When operated under an illumination of 370 nm light with a power density of ∼ 0.5 mW/cm2, the device exhibited an excellent responsivity of 0.185 A/W, a large detectivity of 1.75×1012 Jones, and excellent stability and repeatability. The device also exhibited a high on/off photocurrent ratio up to 103, and a short rising and falling time of 499/412 μs. By integrating the pyro-phototronic effect, the maximum responsivity and detectivity increased significantly to 0.25 A/W and 2.30×1012 Jones, respectively. The response/recovery time was drastically reduced to 79/132 μs without an external power source. In addition, the effects of light wavelength, power density, and bias voltage on the photocurrent response mediated by the pyro-phototronic effect were systematically characterized and discussed. Our work not only provides an easy yet efficient procedure for constructing a self-powered ultraviolet photodetector but also broadens the application prospects for developing individual wire optoelectronic devices based on the photovoltaic-pyro-phototronic effect.

Pyro‐Phototronic Effect in n‐Si/p‐MoO3−x Heterojunction: an Approach to Improve the Photoresponse of the Ultraviolet Photodetector

“…The obtained performance parameters have been compared with the previous literature reports presenting pyrophototronic effects in non-centrosymmetric structured materials are shown in Table 1. [53][54][55][56][57] Based on the comparison, it can be claimed that the presence of the pyro-phototronic effect combined with the photoelectric effect in a MoO 3Àx -based heterojunction shows great potential to enhance the performance of optoelectronic devices which is associated with the combined results of both effects which can be a novel approach to enhance the overall performance in the UV photodetector.…”

Pyro-phototronic effect enhanced broadband photodetection based on CdS nanorod arrays by magnetron sputtering

“…The decreasing trend of the pyro-phototronic effect with increasing bias voltage is related to the emergence of joule heating, which is more deeply affected under the application of large bias voltage. 38,39 As shown in Fig. 5c, an increase in bias voltage is accompanied by a decrease in E (= I pyro+photo /I photo ), with E reaching a maximum of 13.48 at 0 V bias voltage and a minimum value at 3 V bias voltage, which proves that joule heating caused by the bias voltage weakens the pyrophototronic effect.…”

Enhancing UV photodetection performance of an individual ZnO microwire p–n homojunction via interfacial engineering

“…The cross-sectional diameter of the MWs ranges from 1 to 50 μm, and the length reaches up to about 2.5 cm. 24,51,52…”