Non-technical: Many of the present day technologies rely heavily on rare and expensive solid materials. The demand for such materials is on the rise globally due to population growth and emergence of new technologies. The material resources on earth's crust are limited and hence, smart use of materials is required for sustainability. Solar cells are a major renewable energy technology that requires tremendous amounts of materials when it becomes a major contributor to global power production. Use of rare materials will make the technology cost prohibitive in such a scenario. Thus, high availability of materials, especially light absorbers, is an important criterion for an impactful solar cell technology. The materials should also be environmentally benign and make the devices highly efficient, stable and inexpensive. Currently available solar cell technologies based on inorganic or organic materials do not satisfy one or more of these criteria. For example, silicon solar cells are relatively expensive while organic solar cells suffer from stability issues. Some inorganic compounds composed of two or more earth abundant elements like copper, tin, zinc and sulfur potentially fulfill all these criteria. Nevertheless, none of the cells employing these materials have yet yielded efficiencies sufficient to make the technology commercially successful. This EAGER aims at testing a new device configuration for solar cells based on earth abundant inorganic light absorbing materials to dramatically enhance the efficiency. The technology has the potential to make very positive impacts on society as well as environment. For example, a low cost environmentally benign flexible solar cell technology will promote use of solar cells in domestic sector and consumer products. The Principal Investigator will use this project as a platform for educating high school physics teachers who do not have a significant background in physics under Physics Science Teacher Equity Project at University of Houston. High school students from school districts in and around Houston as well as undergraduate students, especially those from minority and less privileged groups, will also be given opportunities to participate in different aspects of this project.
A new organic-inorganic hybrid solar cell configuration compatible with flexible device technology employing absorbers composed completely of earth abundant elements has been proposed. The overall objective of this EAGER project is to test the hypothesis that this configuration based on nanostructured materials could bring breakthrough results in the performance of such solar cells. Low open circuit voltage (Voc) has been recognized as a major factor limiting the efficiency of cells consisting of earth abundant light absorbers. The proposed configuration is designed to primarily address this problem. Processes compatible with flexible solar cells will be used to develop the proposed device structure. Feasibility studies on transparent flexible substrates will also be performed. Fundamental studies will be carried out to understand the materials properties and device performance. This project is both scientifically and technologically relevant. The technological importance arises from the fact that it is aimed at ultimately realizing a low cost highly efficient flexible solar cell made of an environmentally benign absorber material composed of plentiful elements. The fundamental material and device characterizations done under this project work is expected to bring invaluable scientific understanding about the earth abundant light absorber as well as the devices that utilize the new nanomaterial based organic-inorganic hybrid configuration.
