Design and Simulation of Intermediate Band Solar Cell With Ultradense Type-II Multilayer Ge/Si Quantum Dot Superlattice

作者：Tsai Yi Chia; Lee Ming Yi; Li Yiming^*; Samukawa Seiji

来源：IEEE Transactions on Electron Devices, 2017, 64(11): 4547-4553.

DOI：10.1109/TED.2017.2755069

• Conversion efficiency
• density of states (DoSs)
• Ge/Si quantum dot (QD)
• layer distance
• minibands
• multilayer
• solar cell
• superlattice

We studied the miniband dependence on the structural parameters and shape in type-II multilayer germanium (Ge)/silicon (Si) quantum dot superlattice (QDSL) solar cell. A maximum tunable range of ground-state energy is 19% by tuning layer distance down to 0.5 nm, whereas 24.5% is achieved by adjusting the horizontal dot-to-dot spacing down to 0.3 nm. The reduction of effective bandgap is severe for cylindrical QDs than ellipsoidal and conical QDs in the ultradense QDSL, thus leading to a relatively lower conversion efficiency. On average, the thickness of QD shows a negative correlation to conversion efficiency. We observed a high conversion efficiency of 27.22% in a bilayer conical QDSL under an AM1.5 spectral irradiance and one sun illumination.

• 出版日期2017-11