Functionally graded tungsten–copper bimetallic compact with fine microstructure and good mechanical property has been synthesized by employing microwave heating method at a temperature of 800 °C and in a short processing time of 30 min. Scanning electron microscopy and energy dispersive X-ray analysis revealed the graded structure of synthesized sample. The fine microstructure of tungsten in each layer is caused by arrested grain growth because of the short sintering time. The overall relative density of the W/Cu functionally graded sample has reached 87% of the theoretical density. Vickers microhardness measurements, across the length of a compact, show increase in hardness value of the sample with the increase in tungsten content. The experimental hardness values match well with the theoretically calculated hardness values.

The biohybrid photoelectrodes have been studied for photovoltaic applications. The hybrid solar cells were prepared using natural dyes and sputtered zinc oxide (ZnO) thin films on fluorine-doped tin oxide substrate. The natural dyes were extracted from basil (tulsi) leaves, spinach, thor (chhitar thor opuntia or prickly pear), pomegranate and sunflower. The dye-modified photoelectrodes expands the light absorbance of the solar spectrum. They have shown an enhancement in photocurrent and photovoltage under illumination relative to the unmodified photoelectrodes. The photovoltage and photocurrent of hybrid cells were measured to test the devices under light in active area of 1${\times}$1 cm$^2$. The hybrid solar cells have achieved solar energy conversion efficiency from 0.01 to 0.1%. Hybrid solar cells may lead to inexpensive and environment friendly solar energy conversion applications, such as solar electricity and solar fuels.