One of the key requirements to improve the efficiency of solar cells is to be able to couple the energy from the external source to the harvesting device in the optimum manner. For this you need broadband electromagnetic coupling. In photovoltaics, the glass-air barrier typically reduces the coupling due to the Fresnel reflections, and nature has inspired a number of solutions by tuning the refractive index at the interface. What are the most efficient routes to doing this that is also amenable to application on large areas so has to be scalable and broadband.
We have tried the following: https://www.researchgate.net/publication/296847813_Ultra-broadband_light_trapping_using_nanotextured_decoupled_graphene_multilayers
Can this technology be used in more than just solar cells, but also other energy harvesting devices ...
Article Ultra-broadband light trapping using nanotextured decoupled ...
Basic architechture of thin film solar cells is a stacking of a number of functional layers, and, light intensity distribution within devices depends on thin film optics. Therefore, optimization of effective optical constams and thinkness of eacj layer is required to minimize device reflectamce and light absorptance at the position of active layers (ALs) The most common mistake is neglecting parasitic absorptance of electron- and/or hole-extraction layers.
Taking advantage of forward light scattering that can alter and make effective travel distance longer is also useful in enhancing light harvesting efficiency. Photonic structures for light trapping at ALs and photon recycling are another useful strategy.
as Soonil Lee. Also, we have to enhance R&D-optimization on (existing and) new photonic structures(a selective copying from Soonil Lee), in future strategies as a tool for energy harvesting.
Why do you want to improve the efficiency? That is not a silly question - and it has a number of answers! As solar energy is free, it doesn't matter what the efficiency of any given converter is, if you want a bigger output you just use more converter. However, that is not the same as getting more power for a given capital cost of converter. If you can increase the efficiency of useful absorption of solar energy by F1 by increasing the system cost by a factor of say F2, then you have a winning proposition only if F1>F2. This puts a tight cost constraint on efficiency improvement processes. But good luck with your research!
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