Perovskite solar cell

About: Perovskite solar cell is a research topic. Over the lifetime, 4701 publications have been published within this topic receiving 216807 citations. The topic is also known as: PSC.

Molecular versus polymeric hole transporting materials for perovskite solar cell application

Abstract: The p-type semiconducting organic layer used in perovskite solar cells (PSCs) for the hole extraction and transport is a key component of the device to achieve high performance. Organic hole transporting materials (HTMs) can be essentially divided into two subclasses depending on their molecular weight: molecular and polymeric. In the present paper, we fully characterize and compare the electrical response of PSCs prepared with the benchmark molecular Spiro-OMeTAD HTM and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) selected as a low-cost and efficient polymer HTM. For both compounds, cells have been prepared without and with doping. Doping the molecular HTM with bis(trifluoromethane)sulfoimide (LiTFSI) and 4-tert-butylpyridine (tBP) gives rise to a dramatic power conversion efficiency increase from 5.1% to 17.7%. Impedance spectroscopy investigation of the cells shows that the performance of undoped Spiro-OMeTAD cells is limited by the HTM layer resistance and by the strong charge recombination occurring at the HTM/perovskite interface. In the case of P3HT-based devices, the cell performance is increased by doping to a much less extent. Using LiTFSI and tBP additives leads to the best performance. In impedance spectra, they eliminate the intermediate frequency inductive loop. The additives limit the charge recombination at the interface, reduce the interfacial defects and favor the hole transfer from the perovskite to the HTM layer. Importantly, we show that the P3HT conductivity is not the main limiting parameter of the cell efficiency because of the intrinsic conducting properties of the thiophene chain and that increasing the interchain order does not produce a significant enhancement of the PSC efficiency.

Hydrophobic coating over a CH3NH3PbI3 absorbing layer towards air stable perovskite solar cells

Abstract: Lead halide perovskite solar cells with high efficiency have recently attracted tremendous attention. However, the poor stability of perovskite materials has hindered their practical applications. Here, we presented a hydrophobic agent, fluoroalkyl silane, to modify both the light absorbing layer and the hole transport layer. In the presence of a hydrophobic coating, we obtained a stable perovskite solar cell with less hysteresis between the forward sweep and the reverse sweep in air. The effect of fluoroalkyl silane concentration on the stability was investigated; with an optimized 2.0 wt% fluoroalkyl silane solution treatment, the efficiency of perovskite solar cells has reached over 12.0 ± 0.4%. Moreover, for those perovskite solar cells that are exposed to air with about 50% relative humidity, the efficiency was maintained at around 12% for a duration of more than 500 h, while the efficiency of those without hydrophobic coating sharply decreased from about 12% to 1% in a duration of 250 h.

Graphene oxide based planar heterojunction perovskite solar cell under ambient condition

Abstract: Herein, we developed a highly stable planar heterojunction perovskite solar cell (PSC) with a novel architecture (ITO/GO/PEDOT:PSS/MAPbI3/PCBM/carbon tape). The PSC was developed under atmospheric conditions using GO/PEDOT:PSS as a hole transport layer and carbon tape as a back contact. The fabricated device showed good stability and performance with a power conversion efficiency of 5.2%. The fabricated devices were exposed to ambient condition for 96 h to show excellent stability. Remarkably, we found that the stability of the planar heterojunction perovskite solar cell was attributed to the presence of GO, which inhibited direct contact between PEDOT:PSS and MAPbI3.

Decoupling Interfacial Charge Transfer from Bulk Diffusion Unravels Its Intrinsic Role for Efficient Charge Extraction in Perovskite Solar Cells

Abstract: In a perovskite solar cell, the overall photoinduced charge-transfer (CT) process comprises both charge diffusion through the bulk to perovskite/electrode interfaces and interfacial electron and hole transfer to electrodes. In this study, we decoupled these two entangled processes by investigating the film thickness-dependent CT dynamics from CH3NH3PbI3 perovskites to [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) (electron acceptor) and spiro-OMeTAD (hole acceptor). By fitting ultrafast transient absorption kinetics to an explicit “diffusion-coupled charge-transfer” model, we found that the charge diffusion from the film interior to perovskite/electrode interfaces took ∼200 ps to a few nanoseconds, depending on the thickness of perovskite film; the subsequent interfacial charge transfer was ultrafast, ∼6 ps for electron transfer to PCBM and ∼8 ps for hole transfer to spiro-OMeTAD, and led to efficient charge extraction (>90%) to electrodes in a 400 nm thick film. Our results indicate that the picoseco...