Photovoltaic Pile

Abstract

In a previous communication¹, a retinal type of photovoltaic cell is described in which many inert ‘point’ electrodes are placed in a parallel mosaic arrangement in a small volume of photo-active solution. To indicate that each electrode is a photo-receptor, a separate d.c. amplifier is required. An attempt was then made to construct a multiple-point photovoltaic cell in which all the individual electrodes are connected in series, as shown in Fig. 1. One set of electrodes is kept dark with tape while the other is irradiated as in a thermopile. Only one amplifier¹ is of course needed for this cell. As more light- and dark-electrode pairs are added in series, larger photo-potentials are eventually generated, but at a much slower rate than with the individual point electrodes in parallel; also, with certain photo-active solutes, the transient photo-inductive effect² is greatly enhanced, probably because of the presence of an oxygen-coordinated intermediate or other electron ‘source’ between, say, benzoin and benzil.