Title :
Back surface cell structures for reducing recombination in CZ silicon solar cells
Author :
King, Richard R. ; Mitchell, Kim W. ; Gee, James M.
Author_Institution :
Siemens Solar Ind., Camarillo, CA, USA
Abstract :
Mass-produced terrestrial Czochralski (CZ) silicon solar cells are entering the domain in which bulk diffusion length is comparable to the cell thickness, so that recombination at the back surface can have a significant effect on device performance. Three manufacturable processes that address the problem of back recombination are examined: boron diffusion from a deposited doped SiO2 layer; Al-alloyed layers using screen-printed paste; and use of a collecting n+ layer on the back interdigitated with the positive electrode. 104-cm2 cells fabricated at Siemens Solar Industries using these back surface structures are characterized by current-voltage, spectral response, photoconductivity decay, and SIMS measurements
Keywords :
boron; diffusion; electric current measurement; electron-hole recombination; elemental semiconductors; photoconductivity; secondary ion mass spectroscopy; semiconductor doping; semiconductor materials; silicon; solar cells; spectroscopy; voltage measurement; Al-alloyed layers; Czochralski silicon solar cells; SIMS measurement; Si; SiO2; Siemens Solar Industries; back surface cell structures; boron diffusion; bulk diffusion length; collecting n+ layer; current-voltage measurements; deposited doped SiO2 layer; photoconductivity decay measurement; positive electrode; recombination reduction; screen-printed paste; spectral response measurement; terrestrial solar cells; Alloying; Boron; Current density; Current measurement; Fabrication; Photoconductivity; Photovoltaic cells; Radiative recombination; Silicon; Textile industry;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.519966
