Macroscopic versus microscopic photovoltaic response of heterojunctions based on mechanochemically prepared nanopowders of kesterite and n-type semiconductors
| Autor: | O.P. Dimitriev, D.O. Grynko, A.M. Fedoryak, T.P. Doroshenko, M. Kratzer, C. Teichert, Yu.V. Noskov, N.A. Ogurtsov, A.A. Pud, P. Balaz, M. Balaz, M. Tesinsky |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Semiconductor Physics, Quantum Electronics & Optoelectronics, Vol 20, Iss 4, Pp 418-423 (2017) |
| Druh dokumentu: | article |
| ISSN: | 1560-8034 1605-6582 |
| DOI: | 10.15407/spqeo20.04.418 |
| Popis: | Mechanochemically prepared nanopowder of selenium-free kesterite Cu2ZnSnS4 (CZTS) in combination with n-type semiconductors, i.e., CdS, ZnO and TiO2, was tested in planar and bulk-heterojunction solar cells. The samples have been studied by macroscopic current-voltage (I-V) measurements and Kelvin-probe atomic-force microscopy (KPFM). KPFM images taken under light illumination showed the distribution of the potential across the surface, with negative potential on the n-type semiconductor domains and positive potential on the CZTS domains, which indicated charge separation at the interface of the counterparts. The best result was found for the CdS-CZTS composition, which showed a potential difference between the domains up to 250 mV. These results were compared with the planar heterojunctions of CdS/CZTS and TiO2/CZTS, where CZTS nanopowder was pressed/deposited directly onto the surface of films of the corresponding n-type semiconductors. Again, I-V characteristics showed that cells based on CdS/CZTS heterojunctions have the best performance, with a photovoltage up to 200 mV and photocurrent densities up to 0.1 mA/cm2. However, the carrier generation was found to occur mainly in the CdS semiconductor, while CZTS showed no photo-response and served as the hole-transporting layer only. It is concluded that sensitization of the kesterite powder obtained by mechanochemical method is necessary to improve the performance of the corresponding solar cells. |
| Databáze: | Directory of Open Access Journals |
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