Effect of high-temperature post-deposition annealing on cesium lead bromide thin films deposited by vacuum evaporation

Abstract

The effects of high-temperature (500 °C) post-deposition annealing (PDA) on the properties of cesium lead bromide (CsPbBr3) films deposited by vacuum evaporation were studied. The PDA effectively improved the grain size of the CsPbBr3 films. This improvement of the grain size leads to the improvement of carrier diffusion length from 0.1 µm to 0.5 μm. A CsPbBr3 solar cell fabricated using a CsPbBr3 layer with PDA at 500 °C for 60 min showed a conversion efficiency of 6.62% (VOC = 1.465 V, JSC = 6.57 mA/cm2, and FF = 0.688). Our CsPbB3 solar cell also showed a conversion efficiency of 22.5% (VOC = 1.502 V, JSC = 53.7 mA/cm2, and FF = 0.574) for blue LED light (peak wavelength of 453 nm) with an intensity of 206 mW/cm2.

Pulsed Laser Deposition of CsPbBr3 Films: Impact of the Composition of the Target and Mass Distribution in the Plasma Plume

“…Recently, single source thermal evaporation of CsPbBr 3 precursor material, prepared by a common solution-based multistep approach, was reported to yield films consisting of a mixture of CsPbBr 3 , CsPb 2 Br 5 and Cs 4 PbBr 6 compounds requiring mild post deposition treatments to obtain full conversion to CsPbBr 3 [51]. Therefore, post-deposition annealing of the CsPbBr 3 films deposited by thermal evaporation is a key post-growth step to improve quality and solar cell conversion efficiency [10,40,52]. On the other hand, although single-source vapor deposition is performed using mechano-chemically synthesized halide perovskite powders, different evaporation rates of the multiple components of the compacted target may cause off-stoichiometric transfer.…”

AlGaN as an electron transport layer for wide-bandgap perovskite solar cells

“…5) Several approaches have been developed to improve the efficiency of wide-gap perovskite solar cells. For example, studies have reported the fabrication of wide-gap photoreceivers for optical wireless power transfer by employing CsPbBr 3 with a bandgap E g of 2.3 eV 3,6) and CH 3 NH 3 PbBr 3 with a bandgap E g of 2.3 eV. 7,8) One of the challenges in improving the efficiency of such wide-gap perovskite solar cells is causing the energy loss due to the band offset between the conduction band energy positions of the electron transport layer (ETL) and the perovskite layer.…”

“…When energy is transmitted using monochromatic light, irradiating light with a short wavelength and receiving light using a solar cell made of semiconductor materials matching the energy of the irradiated light improves the transmission efficiency. 3) The conversion efficiency of optical wireless power transfer, η, is described by Eq. ( 1), depending on the light emission efficiency of the light source, η light , the light transmission efficiency, η trans , and the photoelectric conversion efficiency of the photoreceiver, η rec .…”

“…(2), where E ph is the energy of photons absorbed, e is the elementary electric charge, F is the incident photon flux, J sc is the current density, V oc is the open-circuit voltage, and FF is the fill factor of the photoreceiver. 3) Figure 1 shows the relationship between the bandgap and the photoelectric conversion efficiency of the photoreceiver, plotted based on this equation. This figure indicates that the photoelectric conversion efficiency of the photoreceiver improves when using a light source emitting short-wavelength light that has higher energy and uses a light-receiving semiconductor material suitable as the light source for optical wireless power transfer.…”

Nanocrystalline gallium nitride electron transport layer for cesium lead bromide photovoltaic power converter in blue light optical wireless power transmission

“…[3][4][5] Perovskite materials with wider and narrower bandgaps are also investigated for multijunction solar cell applications. 6,7) Apart from photovoltaic power generation, optical wireless power transmission (OWPT) [8][9][10][11] is an important application field for perovskite-based solar cells with a wide bandgap light-absorbing layer.…”