Excimer laser annealing to fabricate low cost solar cells. Final technical report

Technical Report · Thu Aug 01 04:00:00 EDT 1985

OSTI ID:5365066

Greenwald, A C

The objective of this program is to show the feasibility of using excimer lasers for cost effective annealing of ion-implanted emitters in the fabrication of silicon solar cells. The maximum AM1 efficiency achieved by the pulse excimer laser anneal (PELA) process for n/sup +/pp/sup +/ cells was 15.6% for a 2 cm x 2 cm cell with photolithographically-patterned contacts. The maximum AM1 efficiency achieved by this PELA process for 100 mm diameter cells with screen printed contacts was 12%. These results are comparable with both diffused junction cells, and cells fabricated by ion-implantation and conventional furnace annealing. IPEG analyses were used to estimate the cost of laser annealing, furnace annealing with passivating oxide growth, and diffused junction formation on a 3 MW/yr production line. The cost of laser annealing was estimated to be 4.9 cents/watt compared to 7.1 cents per watt for the furnace anneal with oxide growth. However, the latter process was more cost effective. This study shows that the projected efficiency for ion-implanted laser annealed silicon solar cells would be 14%, compared to 16.4% with an oxide passivated furnace annealed cell, or an estimated 13% plus for a diffused junction cell. The module costs for these three processes were estimated as $6.56/watt, $5.81/watt, and $6.20/watt respectively. For crystalline silicon solar cells, ion-implantation with furnace anneal and surface oxide passivation would be the preferred process at this production level.

• Research Organization: Spire Corp., Bedford, MA (USA)
• DOE Contract Number: NAS-7-100-956797
• OSTI ID: 5365066
• Report Number(s): DOE/JPL/956797-04; ON: DE86015247
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ANNEALING
COST ESTIMATION
DIRECT ENERGY CONVERTERS
ELECTRIC CONTACTS
ELECTRICAL EQUIPMENT
EQUIPMENT
EXCIMER LASERS
GAS LASERS
HEAT TREATMENTS
ION IMPLANTATION
LASERS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PRODUCTION
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT