Paper TF-ThP25
Performance of WSe₂ Thin Film Photovoltaic Devices as Determined by Numerical Modeling

Thursday, October 31, 2013, 6:00 pm, Room Hall B

Recently the promise of thin film solar cells has begun to be realized on a commercial scale with the introduction of CdTe and CuInGaSe modules in the market place. Although these materials yield cost-effective modules from a dollar/watt aspect they present environmental and possibly long term availability issues. In view of this a great deal of interest is being focused on environmentally safe earth abundant materials including iron sulfide (FeS₂) in the pyrite phase, and tin sulfide (SnS). While promising, iron sulfide is presenting serious material science challenges, while work on SnS is just beginning. In addition the band gaps of these materials are less than the optimal value of 1.36 eV. Another excellent candidate for an earth abundant absorber material is WSe₂ which can be directly grown as a p-type semiconductor with a band gap near 1.4 eV. In view of this we have evaluated the performance of WSe₂ in photovoltaic devices by means of numerical modeling. The model is based on thin film material properties obtained from the literature as well as those measured in our laboratory. These results will be compared to those obtained for FeS₂ where it will be shown that WSe₂ has a significantly higher potential for yielding devices with efficiencies in the 20% range.