TY - GEN
T1 - Metamorphic solar cells employing chemical mechanical polishing and MOVPE regrowth
AU - Mawst, L. J.
AU - Dudley, P.
AU - Kirch, J.
AU - Kim, T.
AU - Ruder, S.
AU - Kuech, T. F.
AU - Tatavarti, R.
PY - 2011
Y1 - 2011
N2 - We have investigated the MOVPE growth of In xGa 1-xAs metamorphic buffer layer (MBL) structures with a focus on techniques to improve the surface morphology and determine the influence of morphology on subsequently grown single-junction device structures. To improve the surface roughness of the underlying MBL, Chemical-Mechanical Polishing (CMP) is employed and MOVPE regrowth of single-junction (SJ) solar cells on top of the polished surface is performed. AFM image analysis indicates the CMP process is effective in reducing the step-graded In xGa 1-xAs MBL surface roughness from ∼7-10 nm (as-grown) to 2.3 nm post CMP. A post-CMP ozone/HF treatment was found to be effective in removing silica residue remaining on the surface from the CMP process, allowing for the growth of films on top of the MBL surface subjected to CMP. Improved short circuit current density (J sc) and external quantum efficiency (QE) were obtained from SJ (1eV) devices which employ the CMP process compared with those on as-grown MBLs.
AB - We have investigated the MOVPE growth of In xGa 1-xAs metamorphic buffer layer (MBL) structures with a focus on techniques to improve the surface morphology and determine the influence of morphology on subsequently grown single-junction device structures. To improve the surface roughness of the underlying MBL, Chemical-Mechanical Polishing (CMP) is employed and MOVPE regrowth of single-junction (SJ) solar cells on top of the polished surface is performed. AFM image analysis indicates the CMP process is effective in reducing the step-graded In xGa 1-xAs MBL surface roughness from ∼7-10 nm (as-grown) to 2.3 nm post CMP. A post-CMP ozone/HF treatment was found to be effective in removing silica residue remaining on the surface from the CMP process, allowing for the growth of films on top of the MBL surface subjected to CMP. Improved short circuit current density (J sc) and external quantum efficiency (QE) were obtained from SJ (1eV) devices which employ the CMP process compared with those on as-grown MBLs.
UR - http://www.scopus.com/inward/record.url?scp=84861081426&partnerID=8YFLogxK
U2 - 10.1109/PVSC.2011.6186007
DO - 10.1109/PVSC.2011.6186007
M3 - Conference contribution
AN - SCOPUS:84861081426
SN - 9781424499656
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 517
EP - 520
BT - Program - 37th IEEE Photovoltaic Specialists Conference, PVSC 2011
T2 - 37th IEEE Photovoltaic Specialists Conference, PVSC 2011
Y2 - 19 June 2011 through 24 June 2011
ER -