Joseph J. Loferski

Application of luminescence in studies of photovoltaic properties of Cu-Cd-S solar cells

This paper shows how the cathodoluminescence (CL) spectrum of chalcocite and tetragonal (not djurleite) films like those in Cu-Cd-S solar cells can be used to develop information about post-fabrication treatments and aging processes. Through the application of CL, it is proposed that Cu-treatment in vacuum always improves the CuxS stoichiometry and post-fabrication treatments in air may lead to the generation of a copper oxy-sulfide layer on the surface and a decrease in surface recombination losses. By the application of CL, initial evidence indicated that Philips dry method and sulfurization method seem to provide stable cell structure.

Thin films and solar energy applications

Abstract Solar energy is diffuse (1 kW m 2 at sea level) and its large scale utilization will require covering very large areas with solar energy conversion devices. For example, to produce all the electrical energy consumed in the US today, about 10,000 km2 of its area would need to be covered by devices which can convert sunlight into electricity with an efficiency of 10%. Economic considerations dictate that thin films will play a central role in the exploitation of solar energy. This paper will review the use of thin films in solar-thermal and solar-photovoltaic converters. In the former, thin film selective absorbers can increase the efficiency with which sunlight is transformed into heat. The problems of thermal absorber surfaces for concentrator systems will be discussed. In the case of solar-photovoltaic converters, the criteria for selection of appropriate semiconductors; grain size considerations; grain boundary problems: anti-reflection coatings and thin metal films in contacts will be discussed. The state of the art in selected thin film systems including the CuxS/CdS cell; the indium tin oxide on silicon cell and the metal insulator silicon cell; the CuInSe2/CdS and the amorphous silicon cell will be discussed.

Photovoltaics IV: Advanced materials: Both polycrystalline and tandem cells promise higher efficiencies than silicon

Considers the use of compound semiconductors for the fabrication of solar cells with high efficiency such as polycrystalline, tandem and single-crystal cells. The variety of compounds showing promise for this application are mentioned, as are several binary compound semiconductors which are presently under study. The low-cost processes being developed for the fabrication of solar cells are also briefly mentioned.

Stoichiometric effects on the properties of copper based chalcopyrite I–III–VI2 semiconductor thin films

Abstract The electrical and optoelectronic properties of CuInSe2, CuInS2, CuGaSe2 and their alloys can be readily controlled by adjusting the stoichiometry of the materials, sometimes by small amounts as in the case of the chalcogenide constituent, sometimes by large amounts as in the case of the copper content. The main movitation for research on these materials is their promise as the active semiconductor of thin film photovoltaic solar cells. The paper reviews investigations of the effects of stoichiometry on the properties of these materials and on their performance is solar cells.

Conversion of Solar Energy Using Tandem Photovoltaic Cells Made from Multi-Element Semiconductors

In preceding chapters, the discussion has focused on solar cells in which the photovoltaically active semiconductor is the element silicon or a binary semiconductor like GaAs, Cu2S, InP, etc. This chapter is concerned with solar cells in which the photovoltaically active semiconductor is based on three or more elements. Specifically, three groups of such semiconductors will be considered, namely, (1) semiconductors which are alloys of binary semiconductors (e.g. AlxGa(1-x)As or GaxIn(1-x)PyAs(1-y)); (2) “true” ternary semiconductors (e.g. CuInS2, CuInSe2) and (3) alloys of these true ternaries (e.g. CuInS2Se2(1-z), z < 1.0).

Science, Technology and the Economic Salvation in Poland: Myths and Reality

During the four decades since the establishment of the Polish People’s Republic, Poland has educated a very large number of well qualified scientists and engineers in the expectation that they would play a central role in the development of the country. That they are well prepared to contribute to science and technology is demonstrated by the ease with which they fit into the best laboratories in the West when they work there as visiting scientists. However, in their own country, their talents are grossly underutilized and, therefore, the country is not benefiting from this rich national resource. One reason for this undesirable situation is Poland’s failure to devise an effective way to transfer technology from the laboratory to industry. The Polish government has encouraged small scale enterprises for transferring technology from the laboratory to the marketplace. However, the economic system does not allow these enterprises to grow as they need to in order to contribute significantly to the national economy. Nor have the Polish planners devised effective ways for transferring S&T results into large state new enterprises. Consequently, Poland can only expect to see a widening of the technology gap with the major industrial countries and a lack of vitality in its high and medium technology industries.

Photovoltaics I: Solar-cell arrays: Clean and silent, solar-cell arrays are targeted to be competitive by 1986

A general view of the solar power industry briefly mentioning the history and indicating the vast advances made up to the present state-of-the-art in terms of technology and economics. Also indicates the possible contribution of solar-cell produced energy to the overall world demand and consumption provided further economic and technological barriers can be overcome. The research and development at present in the fields of solar cell materials, materials growth and the design of solar-cell arrays at present is indicated and the direction and goals are pointed out.