Untapped Potentials of Inorganic Metal Halide Perovskite Solar Cells

Abstract

While the rate of improvement for organic lead halide perovskite solar cells is slowing, there has been a dramatic increase in cell efficiencies and in the number of cell demonstrations for inorganic cesium lead halide perovskite (e.g., CsPbIXBr3-X) solar cells in the last 2 years. The higher band gap and thermal stability of CsPbIXBr3-X are desirable for tandem solar cell applications and other optoelectronic devices. It is apparent that these cells are performing well optically, with some reaching 90% of their theoretical current output limits. However, low carrier lifetime and high surface recombination limit the voltages and fill factors of these cells, limiting their performance to only 60% of their theoretical efficiency limits. Appropriate transport layer designs (producing positive band offsets), reducing surface recombination velocities (to 103 cm/s), and improving lifetimes (10 ms) are effective strategies for improving efficiencies, allowing cells with thick absorbers to be fabricated, and achieving efficiencies above 80% of their theoretical limits.

Recent Progress of All‐Bromide Inorganic Perovskite Solar Cells

“…The loss of the open circuit voltage of ≈18% indicates that the energy‐level alignment can be further improved. One of the advantages of the CsPbBr 3 bandgap is the application in multijunction solar cells with PSCs, silicon solar cells, or CIGS solar cells . Another outstanding property of CsPbBr 3 is the high V oc that can minimize the number of serial connections when considering solar module design.…”

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

“…However, the labile organic cationic methylamine (MA) and formamidine (FA) components in the hybrid perovskites easily escape or decompose at high temperature, which leads to poor long‐term stability of hybrid PSCs under heat and high‐humidity conditions 2,3. To overcome the instability issue of the organic cations, a series of heat‐resistant inorganic CsPbX 3 (X: I, Br, or mixed halides) perovskites have been developed for PSCs, which are also tolerant to oxygen exposure and ultraviolet irradiation 4–6. Among all the inorganic perovskites, the mixed halide CsPbI 2 Br has attracted intensive attention due to its excellent thermal/light soaking stability and suitable direct bandgap, potentially in the front cell for perovskite‐silicon hybrid tandem applications 7.…”

Fabrication of Efficient and Stable CsPbI3 Perovskite Solar Cells through Cation Exchange Process

“…The average carrier lifetime increased from 3.4 ns for the control CsPbI 3 to 5.2 and 8.7 ns for the CEG 0.5 MAI and CEG 1.0 MAI CsPbI 3 , respectively, confirming that trap defects have been reduced using the CEG method producing Adv. [2,14] This is still much lower than that of organicinorganic perovskites [28] and could be further improved in the future. 2019, 9,1901685 more compact and voidfree films.…”

“…[1] Inorganic lead halide perov skites have also attracted attention with the number of research work and demon strated efficiencies constantly on the rise [2] due to the elimination of organic cat ions and tolerance to higher processing temperatures.Among inorganic halide perovskites, CsPbI 3 has gained popularity due to the optical bandgap of 1.72 eV, which is suit able for tandem devices combining with either silicon or low bandgap perovskite solar cells. [1] Inorganic lead halide perov skites have also attracted attention with the number of research work and demon strated efficiencies constantly on the rise [2] due to the elimination of organic cat ions and tolerance to higher processing temperatures.…”

“…

and rapid increase in power conversion efficiency (PCE) to 25.2% most recently reported. [2] Phase instability has been the main challenge of CsPbI 3 cells, due to transition to the undesirable nonperovskite yellow phase (δCsPbI 3 ). Although similar bandgap could also be obtained from the organicinorganic mixed halide perovskite by tuning the halide composition, halide segregation could be a source of photo instability.

…”