10.6% Efficient solution-processed Cu2ZnSnS4solar cells via cation substitutions and Li doping
Copper–zinc–tin–sulfide (Cu2ZnSnS4, CZTS) kesterites a promising earth-abundant and non-toxic absorber for next-generation thin-film photovoltaics. However, sulfur-based CZTS solar cells remain limited in performance, largely due to intrinsic defects and interfacial recombination losses. Here, we sy...
| Authors: | , , , , , , , , , , , , , , |
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| Format: | article |
| Publication Date: | 2026 |
| Country: | España |
| Institution: | Universitat Politècnica de Catalunya (UPC) |
| Repository: | UPCommons. Portal del coneixement obert de la UPC |
| Language: | English |
| OAI Identifier: | oai:dnet:upcommonspor::76052b2028fa1ebdbe337f29f8352fff |
| Online Access: | https://hdl.handle.net/2117/460217 https://dx.doi.org/10.1039/d5ta07702h |
| Access Level: | Open access |
| Keyword: | Czts kesterite materials Thin-film photovoltaics Earth-abundant absorbers Non-toxic solar materials Intrinsic defect mitigation Interfacial recombination losses Solution-processed absorbers Solvent engineering strategies 2-methoxyethanol solvent Dimethylformamide solvent Dimethyl sulfoxide solvent Film morphology optimization Optoelectronic property enhancement Cd-alloyed czts Precursor chemistry control Silver cadmium co-alloying Lithium doping Cation disorder suppression Grain boundary passivation Carrier transport improvement Power conversion efficiency Scalable photovoltaic technologies |
| Summary: | Copper–zinc–tin–sulfide (Cu2ZnSnS4, CZTS) kesterites a promising earth-abundant and non-toxic absorber for next-generation thin-film photovoltaics. However, sulfur-based CZTS solar cells remain limited in performance, largely due to intrinsic defects and interfacial recombination losses. Here, we systematically investigate the impact of solvent chemistry and extrinsic doping and compositional engineering on the quality of solution-processed CZTS absorbers. A comparative study of three solvents, 2-methoxyethanol (MOE), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) reveals that all yield phase-pure, and compact films due to a robust Cu+–Sn4+ molecular precursor system, with MOE producing the most uniform morphology and superior optoelectronic properties. Rather than focusing on pure CZTS, the solvent screening is conducted on Cd-alloyed CZTS (CZCTS), as Cd incorporation substantially alters precursor coordination and crystallization behavior. Building on the optimized processing route, a synergistic compositional strategy combining silver (Ag) – cadmium (Cd) co-alloying with lithium (Li) doping is introduced to suppress cation disorder, passivate grain-boundary defects, and enhance carrier transport. As a result, the optimized he optimized absorber delivers a champion device with a power conversion efficiency of 10.6%, placing it among the highest efficiencies reported for solution-processed, selenium-free CZTS solar cells. These results highlight the critical role of solvent engineering coupled with targeted extrinsic doping in overcoming the long-standing limitations of CZTS photovoltaics and provide a scalable pathway toward environmentally benign thin-film solar technologies. |
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