AVS 63rd International Symposium & Exhibition
    Thin Film Tuesday Sessions
       Session TF-TuA

Paper TF-TuA8
Solar Energy Conversion Properties and Defect Physics of ZnSiP2

Tuesday, November 8, 2016, 4:40 pm, Room 105A

Session: Thin Film Photovoltaics
Presenter: Aaron Martinez, Colorado School of Mines
Authors: A.D. Martinez, Colorado School of Mines
E.L. Warren, National Renewable Energy Laboratory
P. Gorai, National Renewable Energy Laboratory
K.A. Borup, Aarhus University, Denmark
D. Kuciauskas, National Renewable Energy Laboratory
P.C. Dippo, National Renewable Energy Laboratory
B.R. Ortiz, Colorado School of Mines
R.T. Macaluso, University of Texas at Arlington
S.D. Nguyen, University of Northern Colorado
A.L. Greenaway, University of Oregon, Eugene
S.W. Boettcher, University of Oregon, Eugene
A.G. Norman, National Renewable Energy Laboratory
V. Stevanovic, Colorado School of Mines
E.S. Toberer, Colorado School of Mines
A.C. Tamboli, National Renewable Energy Laboratory
Correspondent: Click to Email
Implementation of an optically active material on silicon has been a persistent technological challenge. For tandem photovoltaics using a Si bottom cell, as well as for other optoelectronic applications, there has been a longstanding need for optically active, wide band gap materials that can be integrated with Si. ZnSiP2 is a stable, wide band gap (2.1 eV) material that is lattice matched with silicon and comprised of inexpensive elements. From bulk single crystal growth, we have demonstrated the first ZnSiP2 photovoltaic device, and shown that ZnSiP2 has excellent photoresponse and high open circuit voltage of 1.3 V, as measured in a photoelectrochemical configuration. The high voltage and low band gap-voltage offset are on par with much more mature wide band gap III–V materials. Photoluminescence data combined with theoretical defect calculations illuminate the defect physics underlying this high voltage, showing that the intrinsic defects in ZnSiP2 are shallow and the minority carrier lifetime is 7 ns. The favorable results obtained from characterization of bulk material encourage the development of ZnSiP2 as a photovoltaic absorber material. To pursue this development, we have constructed a thin film growth reactor. This reactor employs a combination of ultra high vacuum chemical vapor deposition, using silane and phosphine as precursor gases, and physical vapor deposition, using an effusion cell to evaporate elemental Zn. The preliminary results of the first stages of thin film growth will be presented in addition to an overview of our characterization of bulk ZnSiP2.