Efficient Perovskite Solar Cells over a Broad Temperature Window: The Role of the Charge Carrier Extraction

Abstract

The mechanism behind the temperature dependence of the device performance in hybrid perovskite solar cells (HPSCs) is investigated systematically. The power conversion efficiency (PCE) of the reference cell using [60]PCBM as electron extraction layer (EEL) drops significantly from 11.9% at 295 K to 7% at 180 K. The deteriorated charge carrier extraction is found as the dominant factor causing this degradation. Temperature dependent spectroscopy and charge transport studies demonstrate that the poor electron transport in the [60]PCBM EEL at low temperature leads to inefficient charge carrier extraction. It is further demonstrated that the n‐type doping of [60]PCBM EEL or the use of an EEL (fulleropyrrolidine with a triethylene glycol monoethyl ether side chain) with higher electron transport capability is an effective strategy to achieve HPSCs working efficiently over a broad temperature range. The devices fabricated with these highly performing EELs have PCEs at 180 K of 16.7% and 18.2%, respectively. These results support the idea that the temperature dependence of the electron transport in the EELs limits the device performance in HPSCs, especially at lower temperatures and they also give directions toward further improvement of the PCE of HPSCs at realistic operating temperatures.

The Role of Bulk and Interface Recombination in High‐Efficiency Low‐Dimensional Perovskite Solar Cells

“…Moreover, the exact mechanism behind the generally low fill factors (FFs) in 2D perovskite cells is not well understood. While several studies point to inefficient charge extraction in causing the FF losses, the role of field‐dependent charge generation on the FF in these quantum confined systems has not been elucidated. A comprehensive understanding of all these loss processes is important to enable advancement in the efficiency of 2D perovskite solar cells.…”

CdS as Electron Transport Layer for Low‐Hysteresis Perovskite Solar Cells

“…But unfortunately, carbon‐based materials like fullerenes (PCBM) or graphene are rather expensive and cannot be produced in huge amounts . Additionally, PCBM shows morphological instability in films (i.e., aggregation as well as degradation at high temperatures) …”

Enhancing the Performance of the Half Tin and Half Lead Perovskite Solar Cells by Suppression of the Bulk and Interfacial Charge Recombination

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] However, the toxicity of lead causes big concerns about their large-scale application. So far, lead halide perovskites have been studied mostly in single junction solar cells, and only after about eight years of optimization of the film morphology and device structure they achieved record power conversion efficiency (PCE) approaching 23.0%.…”

“…[5,9,27] Moreover, the bottom charge transport layer also has great influence on the morphology of the perovskite film, which in turn affects the trap states at the interfaces and in the bulk of the perovskite film and therefore the charge recombination in the device. [5,9,27] Moreover, the bottom charge transport layer also has great influence on the morphology of the perovskite film, which in turn affects the trap states at the interfaces and in the bulk of the perovskite film and therefore the charge recombination in the device.…”