Surface barrier and depletion-layer photocells in silicon

Surface barriers between transparent gold or rhodium films and high-resistivity N-type silicon ( > 20 ohm-cm) exhibit strong photoelectric effects. Based on this observation, photocells have been built by electroplating and vacuum deposition and best results were obta#ined by gold evaporation. The evaporation apparatus described which allows one to optimize film thickness by observing the photovoltaic effect during deposition. The photovoltage from the cells is shown as a function of light intensity, temperature, wavelength, and film thickness. Present cells exhibit approximately one-third the efficiency of good commercial solar batteries, and considerable improvement appears feasible. The photocurrent through the reverse biased barrier is shown as a function of light intensity, temperature, wavelength, and bias voltage.