Selective emitter formation using optical thermal heating [of solar cells]

Rapid thermal processing (RTP) using halogen tungsten lamps as a heating source has been successfully applied to the formation of solar cells in one thermal cycle. Here, the authors extend the use of RTP to form high/low doped regions using the properties of the emitting light. They have played with the absorption, reflection and transmittance of the light in order to control the impinging radiation onto the silicon samples. Selective emitters were prepared by these procedures. Sheet resistance variations in the range 20-150 Ω/□ were obtained depending on the processing parameters like lamp power, time and masking procedures