Device Engineering of Perovskite Solar Cells to Achieve Near Ideal Efficiency

Despite the exciting recent research on perovskite based solar cells, the design space for further optimization and the practical limits of efficiency are not well known in the community. In this manuscript, we address these aspects through theoretical calculations and detailed numerical simulations. Here, we first provide the detailed balance limit efficiency in the presence of radiative and Auger recombination. Then, using coupled optical and carrier transport simulations, we identify the physical mechanisms that contribute towards bias dependent carrier collection, and hence low fill factors of current perovskite based solar cells. Curiously, we find that while Auger recombination is not a dominant factor at the detailed balance limit, it plays a significant role in device level implementations. Surprisingly, our device designs indicate that it is indeed possible to achieve efficiency and fill factor greater than 25% and 85%, respectively - even in the presence of Auger recombination

Screening-Limited Response of NanoBiosensors

Despite tremendous potential of highly sensitive electronic detection of bio-molecules by nanoscale biosensors for genomics and proteomic applications, many aspects of experimentally observed sensor response (S) are unexplained within consistent theoretical frameworks of kinetic response or electrical screening. In this paper, we combine analytic solutions of Poisson-Boltzmann and reaction-diffusion equations to show that the electrical response of nanobiosensor varies logarithmically with the concentration of target molecules, time, the salt concentration, and inversely with the fractal dimension of sensor surface. Our analysis provides a coherent theoretical interpretation of wide variety of puzzling experimental data that have so far defied intuitive explanation.Comment: 7 pages, 2 figure

On Gorenstein Surfaces Dominated by P^2

In this paper we prove that a normal Gorenstein surface dominated by the projective plane P^2 is isomorphic to a quotient P^2/G, where G is a finite group of automorphisms of P^2 (except possibly for one surface V_8'). We can completely classify all such quotients. Some natural conjectures when the surface is not Gorenstein are also stated.Comment: Nagoya Mathematical Journal, to appea

Marketing and Data Science: Together the Future is Ours

The synergistic use of computer science and marketing science techniques offers the best avenue for knowledge development and improved applications. A broad area of complementarity between the typical focus in statistics and computer science and that in marketing offers great potential. The former fields tend to focus on pattern recognition, control and prediction. Many marketing analyses embrace these directions, but also contribute by modeling structure and exploring causal relationships. Marketing has successfully combined foci from management science with foci from psychology and economics. These fields complement each other because they enable a broad spectrum of scientific approaches. Combined, they provide both understanding and practical solutions to important and relevant managerial marketing problems, and marketing science is already very successful at obtaining unique insights from big data