Theoretical Investigation of Quantum Tunneling-Driven Electron Transport in InAs/GaAs Quantum Dot Structures for Solar Cell Applications

Quantum tunneling plays a pivotal role in carrier dynamics of InAs/GaAs quantum dot solar cells, particularly in dense arrays for intermediate band operation. Utilizing the WKB approximation, we perform a systematic theoretical study of the tunneling probability and electron transport rate as functions of barrier thickness (۱-۵ nm), quantum dot size (۳-۱۰ nm), effective mass (۰.۰۲۳-۰.۱ mo), barrier height (۰.۴-۱.۰ eV), and temperature. The calculations show a pronounced exponential dependence on barrier parameters, with transport rate dropping by a factor of ۲۹ when barrier thickness increases from ۱ to ۳ nm. Through multi-parameter sensitivity analysis and phase diagrams, we identify optimal design regimes that promote strong electronic coupling between dots. These results offer precise recommendations for epitaxial growth strategies to maximize charge extraction efficiency, contributing to the realization of high-efficiency QD intermediate band solar cells. The limitations of the model and avenues for experimental validation are discussed.

کلیدواژه ها:

Quantum tunneling ، Quantum dot solar cells ، WKB approximation ، Electron transport ، Photovoltaics