Junction solar cells made with molecular beam glow discharge bombardment

The fabrication and characterization of silicon p-n junction solar cells with various glow discharge, unanalyzed, molecular implanted emitter regions is described. Total area simulated air mass one (AM1) power conversion efficiencies without AR coatings or back surface fields are at best 8.2% compared to 9.1% for conventionally implanted or POC1₃ thermally diffused cells on similar substrates. To achieve optimum performance, Q-switched ruby laser light was incorporated into the molecular implant annealing procedure. Conversion efficiencies greater than 8% were achieved with the four dopants BC1₃, PC1₃ AsF₃ and POC1₃. For similar processing, conversion efficiency with BF₃ implants was less than those of previous investigations, most likely due to poor crystalline regrowth of the heavily doped emitter regions. Cell quantum efficiency and mesa junction ideality are shown to be similar to those of conventional cells while molecular implant sheet resistance values varied, generally being directly related to the dopant molecular weight. Work submitted in partial fulfillment of Ph.D. in Electrical Engineering at the Univ. of Missouri, Columbia, MO 65211