Research Progress on the Application of Lanthanide-Ion-Doped Phosphor Materials in Perovskite Solar Cells

Abstract

Perovskite solar cells (PVSCs) are the most promising candidates in third-generation photovoltaic technologies with a certified efficiency of 25.2% within the past decades. They attract increasing attention owing to their ease of fabrication, cost-effectiveness, and lower processing temperature when compared to commercial silicon-based solar cells. However, some of the striking disadvantages including the low stability, toxicity of the lead element, and hysteresis effect limit the photovoltaic performances and commercialization of the PVSCs. Furthermore, the insufficient utilization of the solar spectrum in commonly used PVSCs due to the spectral mismatch between the solar spectrum and the bandgap of the perovskite is an obstacle to improving the efficiencies of PVSCs. In this regard, lanthanide-doped luminescent materials are implemented in PVSCs for the conversion of a broad spectrum of light into photons of resonant wavelengths through upconversion (UC), downconversion (DC), and downshifting (DS) processes, which are employed to decrement the losses in the energy conversion processes of solar cells. Interestingly, the lanthanide-based UC/DC processes facilitate improved sensitization, light scattering, and stability in PVSCs. Moreover, the lanthanide ions are directly doped into transporting layers for tuning the band alignment, which is an efficient way to enhance the charge carrier transportation, and it is desirable to enhance the power conversion efficiency (PCE) of devices. In this review article, the insights for various UC and DC materials in PVSCs are discussed. Finally, the challenges with emerging research directions are mentioned for further developments of future luminescent-based PVSCs, and some perspectives for future research are also presented.

Opportunities from Doping of Non‐Critical Metal Oxides in Last Generation Light‐Conversion Devices

“…Wide bandgap MOSs, such as TiO 2 , ZnO, and Ta 2 O 5 exhibit intrinsic n-type doping and a large charges diffusion length, highly desirable properties for a photoanode material. However, the lack of visible light absorption limits their application in specific applications such as water purification employing Decreased charge recombination [187][188][189][190][191] Al FTO replacement [192,193] La Downshifting and scattering in PSCs [194] ZrO 2 Ag + Yb Ag + Tb + Yb Broadband spectral conversion [170,195] artificial UV light source. The most employed approach to overcome this issue relies on the sensitization with an organic dye [205] or a second semiconductor.…”

“…[332] Besides using conversion layers or coatings, the possibility of dispersing spectral conversion phosphors inside mesoporous TiO 2 and ZnO photoelectrodes or the direct doping of these MOs by RE 3+ ions in DSSCs and PSCs was also explored. [194,315] This approach does not solve the intrinsic limitations described above, but may have the additional optical advantage of increasing the scattering of light in the active layer providing a further improvement of the cell's photon absorption.…”

“…Therefore, it can be reasonably inferred that, in the not-too-distant future, the best solution will not come from one single approach alone, but it will be obtained by a wise combination of different beneficial contributions. Significant examples are the combination of: i) broadband sensitizers and RE 3+ ions [170] (Figure 11a); ii) downshifting and scattering when phosphors are dispersed in the DSSCs or PSCs active layer; [194] iii) downshifting coupled to antireflection when phosphors are deposited on the front surface of the cell [333] (Figure 11b); iv) spectral conversion enhanced by plasmonic structures. [334,335]…”

Downconversion Materials for Perovskite Solar Cells

“…Moreover, the incorporation of DC material into the perovskite facilitates sensitization, light scattering, enlarges grain size and improve perovskite film crystallinity, therefore enhancing the PSCs' performance and stability. [60][61][62] Under UV exposure, the long-term ambient stability is also enhanced by improving the crystallinity of the perovskite film after doping with DC material. [63] DC materials doping into perovskite also improves the charge carrier lifetimes and leads to efficiency enhancement of PSCs.…”

Cathodoluminescence of zinc oxide crystals grown from melt under high pressure in the presence of ytterbium oxide

“…Zinc oxide is one of the most promising semiconductors for solar cell up-and downconverters because it's cheap and appropriate host for lanthanides [1,2]. The lanthanides atoms on ZnO surface can effectively convert UV and visible light into near-infrared range where the c-Si solar cells strongly absorb light [3][4][5][6]. The light conversion can occur through non-radiative energy transfer from excited state of ZnO to the excited states of lanthanide ions with subsequent light emission in the infrared range [7][8][9].…”