A Review: Thermal Stability of Methylammonium Lead Halide Based Perovskite Solar Cells

Abstract

Perovskite solar cells have achieved photo-conversion efficiencies greater than 20%, making them a promising candidate as an emerging solar cell technology. While perovskite solar cells are expected to eventually compete with existing silicon-based solar cells on the market, their long-term stability has become a major bottleneck. In particular, perovskite films are found to be very sensitive to external factors such as air, UV light, light soaking, thermal stress and others. Among these stressors, light, oxygen and moisture-induced degradation can be slowed by integrating barrier or interface layers within the device architecture. However, the most representative perovskite absorber material, CH3NH3PbI3 (MAPbI3), appears to be thermally unstable even in an inert environment. This poses a substantial challenge for solar cell applications because device temperatures can be over 45 °C higher than ambient temperatures when operating under direct sunlight. Herein, recent advances in resolving thermal stability problems are highlighted through literature review. Moreover, the most recent and promising strategies for overcoming thermal degradation are also summarized.

Thermal stability of mobility in methylammonium lead iodide

“…This temperature is in agreement with the phase transition temperature of MAPbI 3 [53,54]. As the temperature increases, the symmetry of crystalline structure increases and transforms to cubic near 350 K and MA cations become disordered [19,20,[55][56][57]. It is however noteworthy that even when the samples are visibly yellow (e.g.…”

Structural stability and optoelectronic properties of tetragonal MAPbI3 under strain

“…According to previous studies [32][33][34][35][36][37] , the structure of MAPbI3 is easy to decompose into two products such as MAI and PbI2 under external environment (such as humidity, temperature, etc. ), which results in aging phenomenon.…”

Enhanced Stability of Perovskite Solar Cells Incorporating Dopant‐Free Crystalline Spiro‐OMeTAD Layers by Vacuum Sublimation

“…However, our results clearly show enhanced thermal stability for perovskite solar cells incorporating vacuum sublimated Spiro-OMeTAD layers. [43] It is important to note that although the photovoltaic behavior is far from the values that can be reached by using LiTFSI and TBP dopants (see Figure 5 and the last line of Table 2), this is the first example in the literature of perovskite solar cells implementing a vacuum sublimated dopant-free Spiro-OMeTAD thin film, which is the most widely used SSHC in this type of devices. While the PCE is drastically decreased for full solution-processed solar cells annealed at 150 °C (2.4%), the ones incorporating vacuum sublimated Spiro-OMeTAD films is significantly higher (4.8% and 6.5% for Spiro-OMeTAD synthesized at RT and 110 °C, respectively).…”