Slow Hot-Carrier-Cooling in a 2D Lead-Iodide Perovskite Film and Its Photovoltaic Device

Abstract

Significantly slow hot-carrier-cooling happens in a multiphase quasi two-dimensional (2D) perovskite film of (BA) 2 (FA) n−1 Pb n I 3n+1 , where BA is butylammonium, FA is formamidinium, and n = 3 nominally. Due to this phenomenon, a linearly polarized multi-peak emission from phases of n = 2, 3, and 4 emerges and the ever-present one from n = ∞ phase blueshifts in the photoluminescence (PL) spectra, excited using a nanosecond pulsed laser with increasing excitation intensities. Furthermore, hot-carrier PL from small n materials also emerges using a continuous wave laser with an intensity of ∼100 mW/cm 2 ; consequently, the abnormal enhancement of the open-circuit voltage through hot-carrier extraction above 300 mW/cm 2 is achieved. Our work may prove that the FA-based 2D perovskite gives a direction to fabricating hot-carrier solar cells that potentially boost the power conversion efficiency.

Improved exciton photoluminescence of Zn-doped quasi-2D perovskite nanocrystals and their application as luminescent materials in light-emitting devices

“…7d). Normally, γ < 1 represents free-to-bound recombination or the Auger effect, 66 and the decreased γ for the 3D phase could be due to the increased thermally-induced defect-mediated nonradiative recombination.…”

Carrier Cooling in Lead Halide Perovskites: A Perspective on Hot Carrier Solar Cells

“…Nanostructures and quantum well structures have been explored to manipulate the HC lifetime and enhance the efficiency of HC extraction in HCSC. For example, two-dimensional LHPs, − with their inherent quantum well structure, hold great potential as a material candidate for HCSC applications. , These materials have already demonstrated numerous advantages in LHP-based photovoltaic applications. Along these lines, further investigations of the HC cooling dynamics of 2D LHPs with varying “n-values” (referring to the number of octahedral layers in one unit cell) would be highly needed.…”