3.1 Describe the main steps of conversion of photons into electrical energy in a photovoltaic solar cell. Giving reasons

[answerhappygod]

3 1 Describe The Main Steps Of Conversion Of Photons Into Electrical Energy In A Photovoltaic Solar Cell Giving Reasons 1 (148.32 KiB) Viewed 75 times

3.1 Describe the main steps of conversion of photons into electrical energy in a photovoltaic solar cell. Giving reasons, name one method suitable for harvesting majority of photons available in sunlight. 3.2 Figure below shows a sketch of an energy band diagram for a next-generation solar cell. The band gaps and thicknesses of five layers used are also given on the diagram. Explain how this device acts as a solar cell when light enters from the front transparent contact (FTO). OB 2 P-type window 1.5.V EF catel 1.5eV i-CdTe n-CaTe 80 nm 100 FTO h h -type (hbdb) Metal 200 nm 1 μπα nm 1460 nm Ohmic contact to p- semiconductor Ohmic contact to n- semiconductor 3.3 What are the main purposes of the two layers at the front and the back with 80 nm thicknesses? 3.4 This is an early stage of development of the next generation solar cells. Giving reasons, suggest two more methods to improve this device structure. 3.5 Explain how a fully developed device could contribute to the photovoltaic process using "Impurity PV Effect" and "Impact Ionisation" processes. 3.6 Discuss the factors that determine the stability and lifetime of this type of solar cells.