Analysis of CNT – Si Heterojuction Solar Cells.

Abstract

In this thesis heterojunction formation of carbon nanotube (CNT) with silicon (Si) is studied to design new kind of solar cells. The nanoscale structure, high mobility and high physical and electrical properties of CNT can be used to improve the efficiency of solar cell. Here we analyzed i-n (CNT in i-side and Si in n-side) heterojunction solar cells. By varying the diameter of carbon nanotube (CNT), the bandgap can be varied according to our desired value. Here we vary the diameter of CNT around I nm to check the characteristics of this solar cell. To form heterojunction of CNT with Si we assumed CNT as intrinsic and an equation has been developed to find the band diagram. We calculated the ShOlt circuit current density (Jsc) by using the data for terrestrial solar irradiance with Air Mass 1.5. Calculation has been made assuming solar cell is ideal. To calculate Fill Factor and Efficiency for different diameter of CNTs. we have calculated the total current density and the open circuit voltage. MA TLAB software has been used for calculation. P-V curve is also plotted to find the maximum power point and from that fill factor (FF) and efficiency (17) is calculated. In this paper we show different open circLlit voltage. short circuit current, fill factor and efficiency for different diameter of CNT. All the parameters decrease with the decrement of diameters of CNT. In oLir model the best efficiency is 22.663% for of 1.92nm diameter of CNT. We compared the efficiency variation for different diameters of CNT and proposed a range of CNT diameter to design the CNT-Si heterojunction solar cells, in which range efficiency remains stable and higher.