KVPY2020PhysicsSemiconductors
A solar cell is to be fabricated for efficient conversion of solar radiation to emf using material A . The solar cell is to be mechanically protected with the help of a coating using material B . If the band gap energy of materials A and B are E A and E B respectively, then which of the following choices is optimum for better performance of the solar cell.
Options
- AE A = 1 . 5 e V ,   E B = 5 e V
- BE A = 1 . 5 e V ,   E B = 1 . 5 e V
- CE A = 3 e V ,   E B = 1 . 5 e V
- DE A = 0 . 5 e V ,   E B = 5 e V
Correct answer
A. E A = 1 . 5 e V ,   E B = 5 e V
Step-by-step solution
Generally we want the electron to cross energy gaps in material A . Not in material- B because its just covering. And E in the A should not be very small otherwise there will be huge heat loss because of large difference in E g and energy of incident photon