Progress toward Stable Lead Halide Perovskite Solar Cells

Abstract

With the rapid developments in lead halide perovskite solar cell technology, record-high power conversion efficiencies have been achieved, and significant research efforts have been directed toward stability, which is still a major challenge facing the commercialization of perovskite solar cell technology. In this review article, we review the research progress that has been made on the stability of perovskite solar cells. We start with an analysis of recently reported operational stability profiles of perovskite solar cells. On the basis of the analysis, we determine the solar cell lifetime (i.e., T 80 values) and the total amount of energy generated during the lifespan of a perovskite solar cell, from which several trends are inferred. In the subsequent sections, we further examine the instability issues associated with various constituents in a perovskite solar cell and the new methods/strategies that have been developed to solve these issues.

A Generalized Crystallization Protocol for Scalable Deposition of High‐Quality Perovskite Thin Films for Photovoltaic Applications

“…It is also noticeable that the 10% MACl mediated solar cells show no hysteresis which is in striking contrast with the solar cells processed without and with MACl contents higher than 20% ( Figure S11, Supporting Information). [41][42][43] As indicated in Figure S12 of the Supporting Information, the solar cell underwent a 6.3% degradation after 66 min continuous illumination, suggesting acceptable stability of our blade-deposited perovskite solar cells. [40] This can be evidenced from the SEM images (Figure 1a) that 10% MACl processed perovskite film showed complete coverage with compact crystal grains, while lots of pinholes appeared in the sample without MACl incorporation and the pinholes become larger with higher MACl additives.…”

Controlled n‐Doping in Air‐Stable CsPbI2Br Perovskite Solar Cells with a Record Efficiency of 16.79%

“…These results indicate that the optimized CsPbI 2 Br PSCs demonstrate better stability than the control devices; the enhanced stability of the optimized PSCs is probably due to the surface passivation effect of CaCl 2 on the perovskite film 40. Operational stability of the optimized CsPbI 2 Br PSC was measured using a Xenon lamp at AM1.5 solar illumination in air (RH: ≈25%) 41–43. As shown in Figure S13 in the Supporting Information, the optimized device without encapsulation can supply a stable efficiency output of over 16% for 150 min.…”

Reducing Detrimental Defects for High‐Performance Metal Halide Perovskite Solar Cells

“…However, for instance, even though a perovskite surface “free” of charged defects is attained, there is evidence that halides located at the grain boundaries are mobile under an electric field. In addition, desorption of MA + cations is known to occur even during mild thermal annealing and/or solar cell operation conditions –. In our view, the development of designing molecules that can anchor the under‐coordinated halides and under‐coordinated cations without disrupting charge excitation and transport in perovskites deserves further attention, but currently the number of reports on this topic is still scarce .…”

“…The situation is more complex when considering the influences of interfaces formed between perovskite and its adjacent layer (e.g., at the interface between TiO 2 and perovskite) . Therefore, characterization and control of defect formation and its concentration are of paramount importance for achieving reproducible high efficiency perovskite solar cells with large area and long‐term stability …”