A depth behavioral understanding for each layer in perovskite solar cells （PSCs） and their inter[acial interactions as a whole has been emerged for further enhancement in power conversion efficiency （PCE）. Herein, NiO@Carbon was not only simulated as a hole transport layer but also as a counter electrode at the same time in the planar heterojunction based PSCs with the program wxAMPS （analysis of microelectronic and photonic structures）-lD. Simulation results revealed a high dependence of PCE on the effect of band offset between hole transport material （HTM） and perovskite layers. Meanwhile, the valence band offset （AEv） of NiO-HTM was optimized to be -0.1 to -0.3 eV lower than that of the perovskite layer. Additionally, a barrier cliff was identified to significantly influence the hole extraction at the HTM/absorber interface. Conversely, the AEv between the active material and NiO@Carbon-HTM was derived to be -0.15 to 0.15 eV with an enhanced efficiency from 15% to 16%.
The interface between graphene and organic layers is a key factor responsible for the performance of graphene-based organic solar cells(OSCs). In this paper, we focus on coating PEDOT:PSS onto the surface of graphene. We demonstrate two approaches, applying UV/Ozone treatment on graphene and modifying PEDOT:PSS with Zonyl, to get a PEDOT:PSS well-coated graphene film. Our results prove that both methods can be effective to solve the interface issue between graphene and PEDOT: PSS. Thereby it shows a positive application of the composited graphene/PEDOT:PSS film on graphene-based OSCs.
Hole transporting layer(HTL) free organometal halide perovskite solar cells have shown great promise in simplifying device architecture,fabrication process and enhancing stability.However,the simple elimination of the HTL from the standard sandwiched configuration suffers from relatively poor device performance;additionally,the mechanism of the HTL-free perovskite solar cell is still unclear.Herein,we applied a one-dimensional modeling program wxAMPS to investigate the planar HTL-free perovskite solar cells by adjusting the absorber thickness,doping and the absorber/back contact band alignment.The simulation results reveal the importance of the moderate absorber thickness as well as the p-doping perovskite rather than intrinsic as in sandwich structure to the overall device efficiency.In the meanwhile,reducing the mismatching of the absorber/back contact by using higher work function back contact material in replacement of commonly utilized Au electrode is more favorable to improve the device performance.Through optimizing,high performance HTL-free perovskite solar cell with efficiency approaching 17%could be achieved.This study is helpful in providing theoretical guidance for the design of HTL-free perovskite solar cells.
