An understanding of the spectrum–property relationship of perovskite solar cells when illuminated by light‐emitting diodes that are used for indoor applications is necessary. Herein, it is aimed to ...explore the influences of correlated‐color temperatures on a MAPbI3‐based device under low‐light conditions. Given an irradiance of approximately 3 W m−2 (or ≈1000 lx), a maximum free carrier generation rate of 1.0 × 1021 m−3 s−1 was found. Additionally, power conversion efficiencies (PCEs) up to 31.97%, 30.36%, and 28.98% with maximum power outputs of 13.66, 13.02, and 16.09 μW could be reached at 3000, 4000, and 6500 K, respectively. Additional increases in the PCEs were observed when high‐energy blue light (in a range of 400–550 nm) was excluded during the current–voltage sweeps. In combination with the surface photovoltage measurements, intense blue light (under 6500 K) had a minimal influence on the photoinduced charge separation signals when compared to those caused by 3000 and 4000 K light. As a solar cell, the PCE reached as high as 34.52%, which corresponded to 73.08% of the thermodynamic limit of its bandgap at 3000 K.
Herein, the impacts of the correlated‐color temperatures (CCTs) of LEDs on a single‐cation perovskite material MAPbI3 are highlighted. Based on the irradiant spectrum, an emphasis is placed on the theoretical prediction of the free carrier generation rate and maximum current density as a function of the CCT.
•We examine the capability of five laser ablation techniques for scribing an FTO film.•A consistent cut with negligible burrs is made by using the flowing water technique.•Thermal damage is very ...small when the ablation is assisted by the flowing water film.•The suggested technique can be used for the P1 scribing of perovskite solar modules.
Fluorine-doped tin oxide (FTO) is one of the conductive layers used in the emerging perovskite solar cell technology, and the layer is typically scribed by a laser beam. However, thermal damage induced by laser deteriorates the scribe quality and in turn reduces the efficiency of the solar panel. This paper compares five different laser scribing techniques for isolating the FTO on the film and substrate sides both in air and water environments. The width and depth of laser-scribed channels, as well as burrs height, produced by using the different techniques were examined and compared. A clean and consistent scribe with negligible burrs was achievable by ablating the FTO film in the flowing water layer. Using this technique, its burr height index was found to reduce by 62.5% compared to the laser scribing of FTO film in air. A three-dimensional transient heat transfer model was also developed in this study to simulate the temperature field of workpiece subjected to the laser scribing in air and in flowing water environments. The thermal damage region was substantially small when the ablation was performed in the flowing water film. This could be a promising technique for the P1 scribing step in the manufacturing of emerging perovskite solar modules.
Abstract
Posttreatment of titanium oxide (TiO
2
) using lithium (Li) and cobalt (Co) precursors is widely adopted to modify the charge quenching property in perovskite solar cells (PSCs); however, ...the fundamental understanding of the effect of the modification layer on the material itself and, consequently, the photovoltaic performance stability is not complete. In this work, in situ X‐ray diffraction measurements show that the Li and Co ions can diffuse into TiO
2
and consequently accelerate the rutile phase transformation. X‐ray photoelectron spectroscopy results reveal the appearance of a Ti
3+
feature in both the Li‐ and Co‐treated samples, suggesting that the treatment ions are partially located at the subsurface/surface of the spin‐cast TiO
2
layer. The Li‐treated TiO
2
exhibits greatly upshifted conduction band edges, which benefits charge extraction properties and improves the average device parameters in a complete PSC. To complement the experiments, density functional theory calculations are performed. While Li treatment initially results in enhanced electronic properties, Li‐treated TiO
2
tends to have more surface vacancies over time and is more susceptible to adsorption and accumulation of iodide ions compared to the Co‐treated sample, which is experimentally supported by surface photovoltage spectroscopy and time‐resolved photoluminescence results.
Posttreatment of titanium oxide (TiO2) using lithium (Li) and cobalt (Co) precursors is widely adopted to modify the charge quenching property in perovskite solar cells (PSCs); however, the ...fundamental understanding of the effect of the modification layer on the material itself and, consequently, the photovoltaic performance stability is not complete. In this work, in situ X‐ray diffraction measurements show that the Li and Co ions can diffuse into TiO2 and consequently accelerate the rutile phase transformation. X‐ray photoelectron spectroscopy results reveal the appearance of a Ti3+ feature in both the Li‐ and Co‐treated samples, suggesting that the treatment ions are partially located at the subsurface/surface of the spin‐cast TiO2 layer. The Li‐treated TiO2 exhibits greatly upshifted conduction band edges, which benefits charge extraction properties and improves the average device parameters in a complete PSC. To complement the experiments, density functional theory calculations are performed. While Li treatment initially results in enhanced electronic properties, Li‐treated TiO2 tends to have more surface vacancies over time and is more susceptible to adsorption and accumulation of iodide ions compared to the Co‐treated sample, which is experimentally supported by surface photovoltage spectroscopy and time‐resolved photoluminescence results.
Photovoltaic materials are impacted by the photoinduced charge separation behavior, which can be further improved by modifying the underlying layer that the perovskite is prepared on top of. The impacts of using alkali salts on porous TiO2 from experimental and computational points of view are investigated to understand such surface passivation of a solar cell device.
Photovoltaic Performance Stability
The most fundamental properties of photovoltaic materials are impacted by the photoinduced charge separation behavior, which can be improved by modifying the ...underlying layer that the perovskite is prepared on top. In article number 2201632, Non Thongprong, Nopporn Rujisamphan, and colleagues investigate the impacts of using alkali salts on porous TiO2 from experimental and computational points of view to provide a better understanding of such surface passivation.
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