Improving Efficiency of Low Cost EFG Ribbon Silicon Solar Cells by Using a SOD Method

String Ribbon Silicon Solar Cells with 17.8% Efficiency

We have fabricated 4 cm cells on String Ribbon Si wafers with efficiencies of 17.8% using a combination of laboratory and industrial processes. These are the most efficient String Ribbon devices made to date, demonstrating the high quality of the processed silicon and the future potential for industrial String Ribbon cells. Cofiring PECVD (Plasma Enhanced Chemical Vapor Deposition) silicon nitr...

Low-Cost High-Efficiency Solar Cells

III-V compound multijunction solar cells enable ultrahigh efficiency performance in designs where subcells with high material quality and high internal quantum efficiency can be employed. However the optimal multijunction cell bandgap sequence cannot be achieved using lattice-matched compound semiconductor materials. Most current compound semiconductor solar cell design approaches are focused o...

Development of Low-cost and High-efficiency Commercial Size N-type Silicon Solar Cells

Electrodeposition of Photoactive Silicon Films for Low-Cost Solar Cells

Here we demonstrate progress on electrodeposition of photoactive silicon films from an environmentally friendly molten CaCl2 electrolyte, which is the first step of a new route to a practical low-cost silicon solar cell. We report electrodeposition of severalmicron thick silicon films on a graphite substrate in a bath of molten CaCl2 containing SiO2 nanoparticles. The best silicon deposits was ...

Lifetime Enhancement and Low-Cost Technology Development for High-Efficiency Manufacturable Silicon Solar Cells

A low-cost, manufacturable defect gettering and passivation treatment, involving simultaneous anneal of a PECVD SiNx film and a screen-printed Al layer, is found to improve the lifetime in Si ribbon materials from 1-10 μs to over 20 μs. Our results indicate that the optimum anneal temperature for SiNx-induced hydrogenation is 700°C for EFG and increases to 825°C when Al is present on the back o...