TY - JOUR
T1 - Creating metal saturated growth in MOCVD for CdTe solar cells
AU - Irvine, Stuart J.C.
AU - Oklobia, Ochai
AU - Jones, S.
AU - Lamb, Daniel Ash
AU - Kartopu, Giray
AU - Lu, Dingyuan
AU - Xiong, Guohua
N1 - Funding Information:
The authors would like to acknowledge funding by the Engineering and Physical Sciences Research Council (EPSRC), United Kingdom via the grant EP/W000555/1 and from the European Regional Development Fund (ERDF) and the Welsh European Funding Office (WEFO) for funding the 2nd Solar Photovoltaic Academic Research Consortium (SPARC II) which supported this research. The authors also acknowledge support from First Solar Inc.
PY - 2023/4/1
Y1 - 2023/4/1
N2 - Determining the thermodynamic conditions in MOCVD growth of II-VI semiconductor materials is not as straightforward as in III-V growth where Group V hydrides are generally used. This paper establishes a technique, using in situ laser reflectometry, to ensure that the thermodynamic equilibrium is under metal saturated growth. This has been applied to the arsenic doping of CdTe solar cells where it was shown that increasing the II/VI precursor ratio resulted in an increase in As dopant incorporation. The growth kinetics were determined by the diisopropyl tellurium (DIPTe) concentration for II/VI precursor ratios above 2. A method is presented where the change in II/VI precursor ratio can be predicted for different positions in a horizontal MOCVD chamber that has, in turn, enabled variation in NA and the solar cell open circuit voltage (Voc) to be determined as a function of the II/VI precursor ratio. This gives new insight to the thermodynamic drivers in MOCVD growth for improved solar cell Voc and is a method that could be applied to MOCVD of other II-VI semiconductors.
AB - Determining the thermodynamic conditions in MOCVD growth of II-VI semiconductor materials is not as straightforward as in III-V growth where Group V hydrides are generally used. This paper establishes a technique, using in situ laser reflectometry, to ensure that the thermodynamic equilibrium is under metal saturated growth. This has been applied to the arsenic doping of CdTe solar cells where it was shown that increasing the II/VI precursor ratio resulted in an increase in As dopant incorporation. The growth kinetics were determined by the diisopropyl tellurium (DIPTe) concentration for II/VI precursor ratios above 2. A method is presented where the change in II/VI precursor ratio can be predicted for different positions in a horizontal MOCVD chamber that has, in turn, enabled variation in NA and the solar cell open circuit voltage (Voc) to be determined as a function of the II/VI precursor ratio. This gives new insight to the thermodynamic drivers in MOCVD growth for improved solar cell Voc and is a method that could be applied to MOCVD of other II-VI semiconductors.
KW - A1. Phase equilibria
KW - A3. Metal organic chemical vapour deposition
KW - B1. Cadmium compounds
KW - B2. Semiconducting cadmium compounds
KW - B2. Semiconducting II–VI materials
KW - B3. Solar cells
UR - http://www.scopus.com/inward/record.url?scp=85147434686&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2023.127124
DO - 10.1016/j.jcrysgro.2023.127124
M3 - Article
AN - SCOPUS:85147434686
SN - 0022-0248
VL - 607
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
M1 - 127124
ER -
