Ion-implanted Schottky barrier solar cell

The effective height of a Schottky barrier solar cell can be increased by implanting a thin layer (∼ 100Å) of impurity of opposite conductivity to that of the substrate. The implanted solar cell becomes insensitive to changes in interfacial oxide, surface state densities and work function. The maximum open circuit voltage thus fabricated was 0.52 V. The short circuit current for this cell was 25 mA cm^-2(without interdigitated metallization or antireflection coating). Open circuit voltage is related to the steepness of the implant doping density gradient near the metal-semiconductor interface. Thus, implantation is superior to diffusion doping in that it provides the doping density gradient of maximum steepness. Analysis shows that the range of the implant must be less than 100Å and the dosage greater than 10¹³cm^-2to achieve maximum open circuit voltage.