Answer Happy

Q4. Solar cells (a) For an organic solar cell, state the working principles with the assistance of showing the energy diagram of the solar cell. (9 marks) (b) For a semiconductor heterojunction p-n structure, draw the energy diagrams of the three possible types of materials. Show the schematic energy diagram of the most typical type of heterojunction p-n structure at equilibrium condition. (8 marks) (c) For a tandem solar cell, design the structures to (1) increase the absorption wavelength region, (2) increase the open-circuit voltage, and (3) increase the short-circuit current. (8 marks)