17 research outputs found
Effect of calcination temperature on the properties of CZTS absorber layer prepared by RF sputtering for solar cell applications
Abstract In present work, we report synthesis of nanocrystalline Kesterite copper zinc tin sulfide (CZTS) films by RF magnetron sputtering method. Influence of calcination temperature on structural, morphology, optical, and electrical properties has been investigated. Formation of CZTS has been confirmed by XPS, whereas formation of Kesterite-CZTS films has been confirmed by XRD, TEM, and Raman spectroscopy. It has been observed that crystallinity and average grain size increase with increase in calcination temperature and CZTS crystallites have preferred orientation in (112) direction. NC-AFM analysis revealed the formation of uniform, densely packed, and highly interconnected network of grains of CZTS over the large area. Furthermore, surface roughness of CZTS films increases with increase in calcination temperature. Optical bandgap estimated using UV–Visible spectroscopy decreases from 1.91 eV for as-deposited CZTS film to 1.59 eV for the film calcinated at 400 °C which is quite close to optimum value of bandgap for energy conversion in visible region. The photo response shows a significant improvement with increase in calcinations temperature. The employment these films in solar cells can improve the conversion efficiency by reducing recombination rate of photo-generated charge carriers due to larger grain size. However, further detail study is needed before its realization in the solar cells
Cost analysis of roll-to-roll fabricated ITO free single and tandem organic solar modules based on data from manufacture
We present a cost analysis based on state of the art printing and coating processes to fully encapsulated, flexible ITO- and vacuum-free polymer solar cell modules. Manufacturing data for both single junctions and tandem junctions are presented and analyzed. Within this calculation the most expensive layers and processing steps are identified. Based on large roll-to-roll coating experiments the exact material consumptions were determined. In addition to the data for the pilot scale experiment presented here, projections to medium and large scale scenarios serve as a guide to achieve cost targets of 5 €ct per Wp in a detailed material and cost analysis. These scenarios include the replacement of cost intensive layers, as well as process optimization steps. Furthermore, the cost structures for single and tandem devices are listed in detail and discussed. In an optimized model the material costs drop below 10 € per m2 which proves that OPV is a competitive alternative to established power generation technologies