Optoelectronic Evaluation and Loss Analysis of PEDOT:PSS/Si Hybrid Heterojunction Solar Cells

Zhenhai Yang,Jiang Sheng,Jichun Ye,Zhaoheng Ling,Zhaolang Liu,Zebo Fang,Juye Zhu,Pingqi Gao

doi:10.1186/s11671-016-1790-1

Abstract

The organic/silicon (Si) hybrid heterojunction solar cells (HHSCs) have attracted considerable attention due to their potential advantages in high efficiency and low cost. However, as a newly arisen photovoltaic device, its current efficiency is still much worse than commercially available Si solar cells. Therefore, a comprehensive and systematical optoelectronic evaluation and loss analysis on this HHSC is therefore highly necessary to fully explore its efficiency potential. Here, a thoroughly optoelectronic simulation is provided on a typical planar polymer poly (3,4-ethylenedioxy thiophene):polystyrenesulfonate (PEDOT:PSS)/Si HHSC. The calculated spectra of reflection and external quantum efficiency (EQE) match well with the experimental results in a full-wavelength range. The losses in current density, which are contributed by both optical losses (i.e., reflection, electrode shield, and parasitic absorption) and electrical recombination (i.e., the bulk and surface recombination), are predicted via carefully addressing the electromagnetic and carrier-transport processes. In addition, the effects of Si doping concentrations and rear surface recombination velocities on the device performance are fully investigated. The results drawn in this study are beneficial to the guidance of designing high-performance PEDOT:PSS/Si HHSCs.

Highlights

Conventional p-n junction silicon solar cells (SCs) dominate photovoltaic (PV) market, the relevant applications have been substantially restricted by relatively high production cost, which can be partially attributed to their complicated fabrication process [1]
Chi et al demonstrated that the conductivity and wettability of the PEDOT:PSS film can be markedly improved by incorporating different additives into the PEDOT:PSS solution, and the performance of PEDOT:PSS/Si hybrid heterojunction solar cells (HHSCs) was greatly enhanced [17]
The short current density (Jsc) that represents the integrated quantum efficiency is calculated by integrating the external quantum efficiency (EQE) spectrum of the cell under the standard AM1.5G illumination [26]

Summary

Introduction

Conventional p-n junction silicon solar cells (SCs) dominate photovoltaic (PV) market, the relevant applications have been substantially restricted by relatively high production cost, which can be partially attributed to their complicated fabrication process [1]. Organic/ silicon (Si) hybrid heterojunction solar cells (HHSCs) that combine the advantages of the Si base with the organic functional layer have attracted much attention [2, 3]. A p-type polymer of poly(3,4-ethylenedioxy thiophene):polystyrenesulfonate (PEDOT:PSS) with a relatively high work function and a wide bandgap has been widely used in HHSCs as a hole-conductive material [4,5,6,7]. Yu et al reported a PCE of up to 13.7% for PEDOT:PSS/Si HHSCs on nanostructured Si through engineering the interface by adding a solution-processed cesium carbonate layer [18]. Liu et al demonstrated a PCE of 15.5% due to increased conductivity through the addition of p-toluenesulfonic acid into PEDOT:PSS as well as enhanced light-harvesting

Methods

Results

Conclusion