COMPARATIVE STUDY OF THE DISTRIBUTION OF STATES IN A-SI:H BY C-V MEASUREMENTS.

The authors report the application of a new capacitance-voltage method for determining the state distribution in amorphous semiconductors. This method is easy to use and thus offers a practical approach for routine studies of these materials. The validity of the method has been demonstrated previously by a comparative study of n-type materials prepared under RF glow discharge conditions. Here, the authors present an experimental density of states map for an n-type material which was prepared in a dc glow discharge system. They also present the conclusions derived from a comparative study of p-type and undoped materials prepared in RF and dc glow discharge systems. It is found that the dopant incorporation and its effect on the density of states are larger in the dc materials. The undoped dc material is found to have a relatively low density of states which corresponds to its superior photovoltaic properties.