Role of the Selective Contacts in the Performance of Lead Halide Perovskite Solar Cells

Abstract

The effect of electron-and hole-selective contacts in the final cell performance of hybrid lead halide perovskite, CH 3 NH 3 PbI 3 , solar cells has been systematically analyzed by impedance spectroscopy. Complete cells with compact TiO 2 and spiro-OMeTAD as electron-and hole-selective contacts have been compared with incomplete cells without one or both selective contacts to highlight the specific role of each contact. It has been described how selective contacts contribute to enhance the cell FF and how the hole-selective contact is mainly responsible for the high V oc in this kind of device. We have determined that the recombination rate is mainly governed by the selective contacts. This fact has important implication for the future optimization of perovskite solar cells. Finally, we have developed a method to analyze the results obtained, and it has been applied for three different electron-selecting materials: TiO 2 , ZnO, and CdS. SECTION: Energy Conversion and Storage; Energy and Charge Transport

Mixed‐Organic‐Cation Tin Iodide for Lead‐Free Perovskite Solar Cells with an Efficiency of 8.12%

“…However, as the applied voltage is elevated, the R rec of the FASnI 3 ‐based device drops quickly, and at 0.4 V, it becomes substantially smaller than that of the (FA) 0.75 (MA) 0.25 SnI 3 ‐based device and close to those of the MASnI 3 ‐ and (FA) 0.25 (MA) 0.75 SnI 3 ‐based devices. Since it is reported by Juarez‐Perez et al, larger R rec at high applied voltages can contribute to higher V oc ,33 we examined the R rec at the high bias of 0.4 V and found it in good agreement with the V oc of the devices. The (FA) 0.75 (MA) 0.25 SnI 3 ‐based device has the largest R rec at high applied voltages, which validates its outstanding V oc as a result of the reduction of recombination rate through cation mixing.…”

New iridium complex as additive to the spiro-OMeTAD in perovskite solar cells with enhanced stability

“…IS has been used in the characterization of PSCs as important tool in the determination of recombination dynamics. 9,15,[23][24][25] R rec has been obtained by fitting the IS data with the previously described equivalent circuits. 9,23,25 Fig.…”

“…9,15,[23][24][25] R rec has been obtained by fitting the IS data with the previously described equivalent circuits. 9,23,25 Fig. 3 reveals the presence of two different recombination regimes, which are observed at low and at high applied voltages, V app , respectively.…”

“…These two regimes have been previously observed and attributed to two different recombination processes. 9,23,25 On the one hand, the recombination rate has a significant effect on the V oc , especially at high V app (close to the V oc ). 9,15 In this region, samples prepared with metal complex additives present higher R rec , which is related to a lower recombination rate, thus inducing the appearance of higher V oc values on the device.…”

Influence of Schottky contact on the C-V and J-V characteristics of HTM-free perovskite solar cells

“…In pace with the enhancement of stability [16,17], the influence of defects was weakened down to an acceptable level [18,19], while the band offsets between the LHM and ETM or HTM remain major factors impeding PCE [15,[20][21][22][23]. ZnO nanorods [24] or PCBM [25], ETM [26] are able to minimize the band offset at the conduction band minimum (CBM) and allow building almost ideal contact at ETM/LHM interface.…”