Precise Control of Crystal Growth for Highly Efficient CsPbI2Br Perovskite Solar Cells

Abstract

All-inorganic perovskite solar cells (pero-SCs) are attracting considerable attention due to their promising thermal stability, but their inferior power-conversion efficiency (PCE) and moisture instability are hindering their application. Here, we used a gradient thermal annealing (GTA) method to control the growth of a-CsPbI 2 Br crystals and then utilized a green anti-solvent (ATS) isopropanol to further optimize the morphology of a-CsPbI 2 Br film. Through this GTA-ATS synergetic effect, the growth of a-CsPbI 2 Br crystals could be precisely controlled, leading to a high-quality perovskite film with one-micron average grain size, low root-mean-square of 25.9 nm, and reduced defect density. Pero-SCs based on this CsPbI 2 Br film achieved a champion scan PCE of 16.07% (stabilized efficiency of 15.75%), which is the highest efficiency reported in all-inorganic pero-SCs. Moreover, the CsPbI 2 Br pero-SC demonstrates excellent robustness against moisture and oxygen, and maintains 90% of initial PCE after aging 120 hr under 100 mW/cm 2 UV irradiation.

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

“…Therefore, high‐quality perovskite films and desirable energy‐level alignments in CsPbI 2 Br PSCs are keys to reducing energy losses and improving V oc . In order to improve the V oc of a CsPbI 2 Br device, Chen et al applied a gradient thermal annealing and antisolvent method to retard the crystallization process of CsPbI 2 Br film, resulting in a uniform and high‐quality perovskite film and an improved V oc of 1.23 V 19. Tian et al introduced an amino‐functionalized polymer, PN4N, as a novel cathode interlayer, demonstrating that the PN4N interlayer is conducive to the quality of the perovskite film, and the conduction‐band alignment between the electron transport layer and perovskite resulted in an improved V oc of 1.30 V 20.…”

Efficient Passivation with Lead Pyridine‐2‐Carboxylic for High‐Performance and Stable Perovskite Solar Cells

“…Despite the impressive high efficiency, the stability of PSCs lags far behind the requirement for future commercialization. [16][17][18][19][20] However, there is still great challenge to obtain long-term stability and further investigation is urgent. [3,9,10] Efforts have been carried out to improve the stability of PSCs such as solvent engineering, [11][12][13] interface engineering, [14,15] composition engineering, and encapsulation.…”

Recent advances on organic‐inorganic hybrid perovskite photodetectors with fast response

“…However, the traditional photodetectors based on silicon (Si) and III‐V compound semiconductors, mainly rely on expensive, slow, complicated processes, such as metal‐organic chemical vapor deposition (MOCVD) and molecular‐beam epitaxy (MBE), which are unable to achieve low cost, large area, flexible solution production. A new class of semiconducting materials called organic‐inorganic hybrid perovskite (OIHP) will lead to a new generation of commercial photodetectors because perovskite films can be prepared by solution method under low‐temperature conditions . In addition, OIHP meterials are emerging with excellent electrical and optical properties in such as low excitonic binding energy, high charge carrier mobility, long carrier lifetime, and charge diffusion length, which have attracted great interest and contributed all various of high‐performance photodetectors .…”