Integrative role of PEDOT: PSS in adjusting the photoresponse efficiency of novel reduced graphene quantum dots/silicon heterojunction for optoelectronics and solar energy conversion applications

Abstract

The urgent need to realize high-efficiency solar cells and photodetectors for commercially available production, considering the cheap price of their preparation, inspired us to apply quantization technology to graphene particles. Therefore, we reported here for the first time manipulating and boosting the photoelectrical performance of the designed rGO-QDs/p-Si heterojunction using PEDOT:PSS interlayer. The structural properties of the employed rGO-QDs (average size ∼ 2 nm) and PEDOT:PSS thin films have been investigated individually using XRD, Raman, and TEM, while the optical properties have been spectrophotometrically inspected. The values of the energy gap and dispersion parameters of each film have been estimated. Toward exploiting the prepared devices in solar cell applications, after analysis of the measured electrical properties, we concluded that the presence of the PEDOT:PSS layer between the two layers of the device led to a significant improvement in the photovoltaic characteristics with Voc ∼ 0.807 Vs, Jsc ∼ 25.76 mA/cm2, FF ∼ 42.49 %, and PCE ∼ 8.83 %. In addition, on the scale of photodetection capability, the PEDOT:PSS modified device achieved outstanding performance with high responsivity (0.84 A/W), external quantum efficiency (196 %), detectivity (1.62 × 1011 cm.Hz0.5/W) and fast on/off switching behavior of 23/15.2 ms as rise/fall time. Such findings reveal an original indirect scenario about the superior photovoltaic and photodetection behavior of the implemented devices suggesting them strongly for efficient optoelectronics and solar cell applications.