Regensburg 2019 – wissenschaftliches Programm
HL 45.19: Poster
Donnerstag, 4. April 2019, 18:30–21:00, Poster E
Intermediate band solar cells - Two photon excitation of transition metal doped indium sulfide — •R. Hildebrandt1, T. Jawinski1, L. Wägele2, H. von Wenckstern1, R. Scheer2, and M. Grundmann1 — 1Universität Leipzig, Felix Bloch Institute for Solid State Physics, Linnéstraße 5, 04103 Leipzig, Germany — 2Martin-Luther-Universität Halle-Wittenberg, Institute of Physics, Von-Dankelmann-Platz 3, 06120 Halle, Germany
The Shockley-Queisser limit for solar cell efficiency of 33.7% is based on a trade-off between generated photocurrent and photovoltage . Intermediate band (IB) solar cells are proposed to overcome this trade-off by an additional two step photon absorption via states within the band gap . Those states may be realized by quantum dots, band anti-crossing in highly mismatched alloys or deep level impurities.
In this work we pursue a deep level impurity approach for IB solar cells. The heterostructure consists of p-ZnCo2O4/i-In2S3/n-ZnO:Al . The transition metal (V, Nb or Ti) doped In2S3 absorber material is deposited by thermal co-evaporation. ZnCo2O4 is deposited by pulsed laser deposition and ZnO:Al by HF-sputtering.
The devices were characterized with photocurrent measurements and with a two photon excitation setup provided by two UV/VIS and IR supercontinuum laser sources. Thermal admittance spectroscopy measurements revealed a sulfur vacancy at 400 meV depth.
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