Novel structures of photonics devices (e.g. photovoltaic cells also called as solar cells) are provided. The Cells are based on the micro (or nano) structures which could not only increase the surface area but also have the capability of self-concentrating the light incident onto the photonics devices. Using of such structures, it is possible to achieve significant performance improvement. For example, if such structures are used in the photovoltaic cells, large power generation capability per unit physical area is possible over the conventional cells, and have enormous applications such as in space, in commercial, residential and industrial applications. Such structures are also beneficial to other photonics devices such as photodetector to enhance the performance.