TY - JOUR
T1 - VxIn(2-x)S3 Intermediate Band Absorbers Deposited by Atomic Layer Deposition
AU - McCarthy, Robert F.
AU - Weimer, Matthew S.
AU - Haasch, Richard T.
AU - Schaller, Richard D.
AU - Hock, Adam S.
AU - Martinson, Alex B.F.
N1 - Funding Information:
Work at Argonne National Laboratory was supported under U.S. Department of Energy Contract DE-AC02-06CH11357. Use of the Center for Nanoscale Materials, an Office of Science user facility, including resources in the Electron Microscopy Center, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC02-06CH11357. M.S.W. acknowledges support from the ARCS foundation. A.S.H. thanks the Department of Energy and the Illinois Institute of Technology for funding and start-up support.
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/4/26
Y1 - 2016/4/26
N2 - Substitutional alloys of several thin film semiconductors have been proposed as intermediate band (IB) materials for use in next-generation photovoltaics, which aim to utilize a larger fraction of the solar spectrum without sacrificing significant photovoltage. We demonstrate a novel approach to IB material growth, namely atomic layer deposition (ALD), to allow unique control over substitutional-dopant location and density. Two new ALD processes for vanadium sulfide incorporation are introduced, one of which incorporates a vanadium(III) amidinate previously untested for ALD. Using this process, we synthesize the first thin film VxIn(2-x)S3 intermediate band semiconductors and further demonstrate that the V:In ratio, and therefore intraband gap density of states, can be finely tuned according to the ALD dosing schedule. Deposition on a crystalline In2S3 underlayer promotes the growth of a tetragonal β-In2S3-like phase VxIn(2-x)S3, which exhibits a distinct sub-band gap absorption peak with onset near 1.1 eV in agreement with computational predictions. However, the VxIn(2-x)S3 films lack the lower-energy transition predicted for a partially filled IB, and photoelectrochemical devices reveal a photocurrent response only from illumination with energy sufficient to span the parent band gap.
AB - Substitutional alloys of several thin film semiconductors have been proposed as intermediate band (IB) materials for use in next-generation photovoltaics, which aim to utilize a larger fraction of the solar spectrum without sacrificing significant photovoltage. We demonstrate a novel approach to IB material growth, namely atomic layer deposition (ALD), to allow unique control over substitutional-dopant location and density. Two new ALD processes for vanadium sulfide incorporation are introduced, one of which incorporates a vanadium(III) amidinate previously untested for ALD. Using this process, we synthesize the first thin film VxIn(2-x)S3 intermediate band semiconductors and further demonstrate that the V:In ratio, and therefore intraband gap density of states, can be finely tuned according to the ALD dosing schedule. Deposition on a crystalline In2S3 underlayer promotes the growth of a tetragonal β-In2S3-like phase VxIn(2-x)S3, which exhibits a distinct sub-band gap absorption peak with onset near 1.1 eV in agreement with computational predictions. However, the VxIn(2-x)S3 films lack the lower-energy transition predicted for a partially filled IB, and photoelectrochemical devices reveal a photocurrent response only from illumination with energy sufficient to span the parent band gap.
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U2 - 10.1021/acs.chemmater.5b04402
DO - 10.1021/acs.chemmater.5b04402
M3 - Article
AN - SCOPUS:84964780429
VL - 28
SP - 2033
EP - 2040
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 7
ER -