TY - JOUR
T1 - Thermal emissivity of silicon heterojunction solar cells
AU - Alonso-Álvarez, D.
AU - Augusto, A.
AU - Pearce, P.
AU - Llin, L. Ferre
AU - Mellor, A.
AU - Bowden, S.
AU - Paul, D. J.
AU - Ekins-Daukes, N.
N1 - Funding Information:
This work was funded by the Engineering and Physical Sciences Research Council grant EP/M025012/1 . A. Mellor was supported by the European Commission through Marie Sklodowska Curie International Fellowship, Grant No. DLV-657359 . P. Pearce would like to acknowledge EPSRC CASE sponsorship from IQE plc. This material is based upon work supported in part by the National Science Foundation and the Department of Energy under NSF CA No. EEC-1041895 . Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of NSF or DOE.
Funding Information:
This work was funded by the Engineering and Physical Sciences Research Council grant EP/M025012/1. A. Mellor was supported by the European Commission through Marie Sklodowska Curie International Fellowship, Grant No. DLV-657359. P. Pearce would like to acknowledge EPSRC CASE sponsorship from IQE plc. This material is based upon work supported in part by the National Science Foundation and the Department of Energy under NSF CA No. EEC-1041895. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of NSF or DOE.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/10
Y1 - 2019/10
N2 - The aim of this work is to evaluate whether silicon heterojunction solar cells, lacking highly emissive, heavily doped silicon layers, could be better candidates for hybrid photovoltaic thermal collectors than standard aluminium-diffused back contact solar cells. To this end, the near and mid infrared emissivity of full silicon heterojunction solar cells, as well as of its constituent materials – crystalline silicon wafer, indium tin oxide, n-, i- and p-type amorphous silicon – have been assessed by means of ellipsometry and FTIR. The experimental results show that the thermal emissivity of these cells is actually as high as in the more traditional structures, ~80% at 8 μm. Detailed optical modelling combining raytracing and transfer matrix formalism shows that the emissivity in these cells originates in the transparent conductive oxide layers themselves, where the doping is not high enough to result in a reflection that exceeds the increased free carrier absorption. Further modelling suggests that it is possible to obtain lower emissivity solar cells, but that a careful optimization of the transparent conductive layer needs to be done to avoid hindering the photovoltaic performance.
AB - The aim of this work is to evaluate whether silicon heterojunction solar cells, lacking highly emissive, heavily doped silicon layers, could be better candidates for hybrid photovoltaic thermal collectors than standard aluminium-diffused back contact solar cells. To this end, the near and mid infrared emissivity of full silicon heterojunction solar cells, as well as of its constituent materials – crystalline silicon wafer, indium tin oxide, n-, i- and p-type amorphous silicon – have been assessed by means of ellipsometry and FTIR. The experimental results show that the thermal emissivity of these cells is actually as high as in the more traditional structures, ~80% at 8 μm. Detailed optical modelling combining raytracing and transfer matrix formalism shows that the emissivity in these cells originates in the transparent conductive oxide layers themselves, where the doping is not high enough to result in a reflection that exceeds the increased free carrier absorption. Further modelling suggests that it is possible to obtain lower emissivity solar cells, but that a careful optimization of the transparent conductive layer needs to be done to avoid hindering the photovoltaic performance.
KW - Emissivity
KW - Heterojunction
KW - Modelling
KW - Silicon
KW - Solar cells
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U2 - 10.1016/j.solmat.2019.110051
DO - 10.1016/j.solmat.2019.110051
M3 - Article
AN - SCOPUS:85068569724
SN - 0927-0248
VL - 201
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
M1 - 110051
ER -