The potential of nanoparticle ink-based processing for Chalcogenide photovoltaics

Nanoparticle ink-based absorber layers coupled with selenization represent a robust method for the formation of chalcogenide photovoltaics with tremendous potential for low-cost, roll-to-roll manufacturing. We first present our current state-of-the-art nanoparticle ink-based devices with total-area efficiencies of 15.0% for Cu(In _y Ga _1-y )(S _x Se _1-x ) ₂ (CIGSSe), 9.0% for Cu ₂ ZnSn(S _x Se _1-x ) ₄ (CZTSSe), and 9.4% for Cu ₂ Zn(S _n yGe _1-y )(S _x Se _1-x ) ₄ (CZTGeSSe). Similarities in the material and electrical properties of devices fabricated from all three material families are considered. Major factors contributing to device performance limitations are discussed in terms of absorber morphology and material properties following selenization, notably, alloy (compositional) fluctuations and the presence of a fine-grain layer. Through analysis of these limitations we also present a path forward for the fabrication of high-performance devices. In spite of the present challenges, this technique outperforms many others, demonstrating the tremendous potential of this technology.