Solar cells with mesh-structured emitter

✍ Scribed by S. W. Glunz; J. Schumacher; W. Warta; J. Knobloch; W. Wettling

• Book ID: 102660569
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 711 KB
• Volume: 4
• Category: Article
• ISSN: 1062-7995
• DOI: 10.1002/(sici)1099-159x(199611/12)4:6<415::aid-pip152>3.0.co;2-1

✦ Synopsis

The mesh-structured emitter solar cell (MESC) is introduced as a novel solar cell processing scheme. By the formation of inverted pyramids or microgrooves on a wafer with a homogeneous heavy phosphorus &$hion, a mesh of highly conducting emitter lines is formed. Using this technique, the lateral conductivity of the emitter can be increased, keeping the emitter dark saturation current at a low level. The high phosphorus surface concentration results in a low contact resistance even for screen-printed contacts. Thus, this technique is ideal for solar cells with screen-printed contacts, because the finger spacing of the front contact can be extended, resulting in smaller shadowing losses. Also the processing scheme of high-eflciency solar cells can be simplified, because the formation of the surface texturization and the locally deep di' used emitter can be combined in one step. The first cells with a mesh-structured emitter, evaporated front contacts and local ohmic rear contacts have shown eficiencies up to 21.1 %. Lifetime test structures have been used to determine a low dark saturation current of 58 f A cm-2 for the mesh-structured emitter, although the structure is not yet optimized.