Photovoltaic solar cells are devices for the direct conversion of sunlight in electrical energy. They use available sunlight and can be used anywhere that sunlight is incident. No other external energy source is used in the process and the cells are ecologically ideal in that they produce no waste. In principle the only limitation they face is the availability of solar radiation although the devices can also function (less efficiently) under reduced light (cloudy) conditions. This invention provides a new method for the construction of such cells based on sensitized semiconductors absorbing sunlight and producing a photocurrent. The method is simple, rapid and versatile and lends a high degree of variation making the testing of new photosensitizers possible. Results are positive.