Enhanced photovoltaic output of bifacial perovskite solar cells via tailoring photoelectric balance in rear window layers with 1T-WS2 nanosheet engineering. (28th June 2022)

• Record Type: Journal Article
• Authors: Fan, Lin; Lü, Wanhong; Hu, Wanting; Han, Donglai; Yang, Shuo; Wang, Dandan; Mai, Zhihong; Wang, Fengyou; Liu, Huilian; Yang, Jinghai; Yang, Lili
• Is Part Of: Materials chemistry frontiers. Volume 6:Number 15(2022)
• Page Start: 2061
• Page End: 2071
• Publication Date: 2022-06-28
• Subjects: Materials science -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1039/d2qm00366j
• Languages: English
• ISSNs: 2052-1529

Abstract

Abstract : A novel organic-inorganic hybrid rear window layer (RWL) was constructed. The photoelectric balance of the hybrid RWL was improved by doping with 1T-phase WS2 (1T-WS2 ). Abstract : The development of high-quality rear window layers (RWLs) with excellent photoelectric properties is key to achieving a high photovoltaic (PV) output from bifacial perovskite solar cells (b-PSCs). Herein, we propose a novel strategy to improve the photoelectric balance of RWLs by introducing 1T-phase tungsten disulfide (1T-WS2 ) nanosheets with metallic properties into a traditional organic hole-transporting layer (HTL) to create an organic–inorganic hybrid model. The mechanisms responsible for the synergistic improvement in the photoelectric and physical properties of the hybrid system, particularly the light-trapping capability, interface properties, charge dynamics, and PV parameters of the b-PSCs, are discussed in depth. The decrease in the thickness of the hybrid HTL due to the introduction of 1T-WS2 not only enhances the optical transmittance, but also accelerates hole transfer in the improved system to a certain extent. Moreover, the decrease in the surface potential of the hybrid HTL driven by 1T-WS2 improves the work function and brings the valence band closer to that of the perovskite. This energy-level alignment caused by Fermi level reduction effectively promotes hole extraction/transfer/collection and suppresses interface recombination, thus improving the PV parameters of devices. Owing to the fact that 1T-WS2 doping synchronously enhances the light-harvesting capability and charge behavior of the device, the obtained maximum efficiencies of the optimized hybrid b-PSC under front and rear illuminations are 19.87 and 15.48%, respectively, which are superior to those of conventional organic b-PSCs. Ultimately, the 1T-WS2 -doped RWL created in this work effectively alleviates the PV degradation caused by water erosion and photo-thermal degradation of b-PSCs during environmental testing. The corresponding unencapsulated devices exhibit excellent irradiation/operational stability. This work provides important insights into the improvement in the photoelectric balance of RWLs in bifacial and tandem devices, and establishes a foundation for the widespread application of two-dimensional transition metal dichalcogenides in high-efficiency PV devices.