The concept of multiband materials has recently emerged as a candidate for third generation photovoltaics.  Conceptually, a multiband material is one with a defect-induced, conductive, delocalized intermediate band lying between the valence and conduction bands of a host semiconductor, as illustrated in

the figure.  At radiative limits, large gains in efficiency are possible, primarily because photons with energies lower than the primary band gap can now be absorbed and utilized as well. 

We are interested in the nature of the formation of the intermediate band through the incorporation of appropriate defects into the host semiconductor, often considered to arise from level repulsion, or band anti-crossing.  We are exploring the nature of defect band formation using electronic structure methods.  Additionally, we are interested in the development of quantum dot structures as multiband materials.  

Multiband Solar

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