Improved Photovoltaic Performance of GaAs/Carbon Nanotube Heterojunction Solar Cells with a Multifunctional Nafion/PEDOT:PSS Layer

Carbonnanotubes (CNTs) have gained significant interestdue totheir potential in enhancing the performance and cost effectivenessof photovoltaic (PV) applications. This study demonstrates the efficacyof an optimal cell configuration for InGaP/GaAs/CNT/sulfonated poly(tetrafluoroethylene)(Nafion)/PEDOT:PSS heterojunction solar cells (HJSCs). This was achievedby adjusting the thickness of the CNT film and the Al2O3 buffer layer. The facile one-step spin coating of the multifunctionalNafion/PEDOT:PSS (NP) layer on the GaAs/CNT surface contributes tohole transportation, surface passivation, and formation of antireflectionand encapsulation, resulting in a high power conversion efficiency(PCE) of 14.2% with better stability over one month of light soaking.Moreover, the corresponding mechanisms of the reaction between thehighly hydrophilic sulfonate group of insulating, chemically stableNafion and PSS in PEDOT:PSS are demonstrated by analyzing the morphology,chemical component, and configuration and their photoelectric properties.This work is highly important for obtaining high-performance, cost-effective,and air-stable SCs for light-harvesting industrial development.