E. Schubert, Rensselaer Polytechnic Institute
Intellectual merit: The refractive index, first introduced by Isaac Newton, is the most fundamental quantity in optical sciences. The intellectual merit of the proposed program lies in the development of a new class of optical thin-film materials with unprecedented low refractive index and in the employment of these thin-film materials in two specific device applications: Solar cells and light-emitting diodes. Each type of device will be coated with highly light-transmissive graded-index layers. Numerous figures of merit in multilayer optical thin-film structures depend on the refractive index contrast, that is, the difference in refractive index between a high- and a low-index material. Thus, many optoelectronic components could be strongly improved if materials with a refractive index close to that of free space would be available. However, the refractive index of conventional dense optical materials is limited to values higher than 1.4. Viable materials with refractive indices in a range n = 1.05?1.20 do not yet exist, but would be of tremendous interest.
Broader impact: In addition to the scientific impact, the proposed program would have a strong educational component. The educational goals of the program are (i) training and furthering of the intellectual growth of graduate students, (ii) raising the interest of undergraduate students, particularly of domestic undergraduate students, and involvement of these students in leading-edge research, and (iii) increased participation of underrepresented and disadvantaged groups. The ability to participate in a new direction of research and in the application of new optical materials in devices provides an excellent opportunity for students to be educated and trained in a novel, interdisciplinary, and potentially high-impact field. Furthermore, low-refractive-index materials will contribute to the pollution-free generation of electricity by solar cells and the highly efficient use of electricity in solid-state lighting devices.
