Hysteresis in Hole-free Perovskite Solar Cells with Carbon Counter Electrode Doped Reduced Graphene Oxide (RGO)

Mohammed Basheer,Shakir Ibrahim,Khalid Gasmalla,Wessam Abdel Salam,Moataz Soliman,N Mastorakis,V Mladenov,A Bulucea

doi:10.1051/matecconf/201821002046

Abstract

Perovskite solar cells achieved high efficiencies but they suffer from the hysteresis of (J-V) curve that depends on the scan direction. The architecture introduced in this paper is hole –free cell with Reduced Graphene Oxide (RGO) as a dopant. The good electrical and optical properties of (RGO) make it acts as a hole transfer layer (HTL) beside its basic role as a dopant of carbon counter electrode. For different areas, the hysteresis decreases by decreasing the cell area. The TiO2/CH3NH3PbI3-xClx interface is truly responsible for the hysteresis in the Perovskite solar cells due to the dependence of the porosity from area to other.

Highlights

In recent few years, perovskite solar cells based on CH3NH3PbI3 and CH3NH3PbI3-xClx have attracted researchers due to their unique properties such as high light absorbance and high power conversion efficiency (PCE) [1]
Perovskite solar cells achieved high efficiencies but they suffer from the hysteresis of (J-V) curve that depends on the scan direction
The origin of hysteresis has been discussed on the intrinsic properties such as ferroelectric polarization [9], ionic migration [10],the charge trapping/detrapping caused by the lattice mismatch or voids at this interface which act as capacitors

Summary

Introduction

Perovskite solar cells based on CH3NH3PbI3 and CH3NH3PbI3-xClx have attracted researchers due to their unique properties such as high light absorbance and high power conversion efficiency (PCE) [1]. The origin of hysteresis has been discussed on the intrinsic properties such as ferroelectric polarization [9], ionic migration [10] ,the charge trapping/detrapping caused by the lattice mismatch or voids at this interface which act as capacitors. In this paper to discuss the relation between the cell area and the hysteresis we used (RGO) [11] as a dopant of carbon counter electrode to enhance its conductivity, moisture impermeability and photoelectric properties. This leads to favorable physical properties, more charge separation and extraction. Hysteresis is usually small for C-PSCs because the thick TiO2 scaffold may eliminate charge accumulation at the TiO2/perovskite interface.[12]

Experimental Works

Perovskite and Cell characterizations

Results

Conclusion