Abstract: A photovoltaic device is provided comprising a layer. The layer comprises a plurality of grains separated by grain boundaries wherein the grains are either p-type or n-type. The grain boundaries comprise an active dopant. The active dopant concentration in the grain boundaries is higher than the effective dopant concentration in the grains. The grains and grain boundaries may be of the same type or of the opposite type. Further, when the grain boundaries are n-type the bottom of the grain boundaries may be p-type. A method of making the layer is also disclosed.

Abstract: A remote sensing system comprises a micro-electromechanical sensor (MEMS) device comprising an optical energy absorbing sensing element that resonates by thermal expansion induced by absorption of optical signals, a remotely located optical source for transmitting driving optical signals to induce resonation in the sensing element, and a remotely located reader circuitry to read an original frequency of the sensing element using reader optical signals for determining a condition to which the MEMS device is exposed.