Photoconductivity in BxCyNz decorated ZnO 2D/1D system: Conjugation of charge transfer and piezo-phototronic effects

Abstract

We present the improvisation of photoresponse characteristics of BxCyNz/ZnO system through the amalgamation of the charge transfer process and piezo-phototronic effect. The nanoflakes of BxCyNz obtained through simple chemical route are characterized by N-deficiency related defects in the network. In contrast to bare ZnO, the enhancement of current under light (by 145 %) in BxCyNz decorated system has been correlated to the defect-assisted charge transfer from BxCyNz to ZnO. Further, the interplay of trap-related space charge current due to excess charge transfer under UV illumination is found to exhibit an anomalous dependency of photocurrent with light intensity. The charge transfer process becomes more effective under the application of strain on the BxCyNz/ZnO system and thus exhibits 6 times higher photoresponsivity (∼44 AW−1) compared to the relaxed system. In this context, the negative piezo-potential mediated modification at the interface is held responsible for favouring the transport of transferred charge. Apart from that, the influence of the structural organization of ZnO system on the piezo-phototronic effect-led UV photodetection has also been observed. Eventually, the moderate photoresponse characteristics in g-C3N4/ZnO system in relaxed and strained platforms, ensure the superior role of N-deficiency related electronic states of BxCyNz in elevating the photoresponse property.