The Enhancement of Visible Photodetector Performance based on Mn doped ZnO Nanorods by Substrate Architecting

Abstract

ZnO is one of the most fascinating and cost-effective materials for numerous applications, especially optoelectronics. To improve its properties and performance, many techniques have been developed, in which doping and surface engineering are usually of interest. Recently, combining techniques for further enhancement has got significant attention but not fully explored. In this study, a new combination to widen the light absorbance of ZnO nanorods (NRs) is introduced. This combination is based on (i) doping of Mn and (ii) substrate architecting. Patterned substrates are formed with master molds as digital video disc (DVD) and lotus leaf through polydimethylsiloxane (PDMS) molding. Mn-doped ZnO NRs were then hydrothermally grown on them at low temperatures. For investigate their morphology, structure and optical properties, scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible spectroscopy (UV-Vis) were employed. The obtained results show that the Mn-doped ZnO samples with the patterned substrates own a remarkable increase (> 40%) in the visible light absorbance as compared to that with the flat substrate due to an increment of light scattering. Besides, a photodetector is fabricated based on the optimized patterning PDMS substrate with the active material of Mn doped ZnO NRs. The results show that the photocurrent of patterning device is 3.8 time higher than that of flat substrate. Overall, our approach for growing Mn-doped ZnO NRs on 3D patterned structures at low temperature is promising for optical applications such as flexible and stretchable optoelectronic devices.