Quantum-dot solar cells

University of Tsukuba VGP-BPS8 successfully quantum-dot solar cell conversion efficiency increased to 8.54%

The International Society of solar cell technology, “EU PVSEC” on the University of Tsukuba made public to the use of quantum dot solar cell of the photoelectric conversion efficiency increased to 8.54% of the technological achievements. Quantum-dot solar cells can VGP-BPS8A reach the theoretical conversion efficiency of more than 60% of well-known is the future of efficient solar cells is one candidate.

Developed by the University of Tsukuba quantum-dot solar cells are pn junction between the multiple quantum dot layers stacked quantum-dot superlattice-based products, in the 1cm square alternately superimposed on the GaAs substrate 30, and 30-layer InAs layer GaNAs super-crystal lattice structure. Its characteristics are in the GaNAs formed on InAs, in order to ease the underlying strain between the lattice can be self-generating high-3 ~ 4nm, diameter of 20 ~ 30nm multiple VGP-BPS9 quantum dots.

Lead to quantum-dot superlattice structure created between combination, in the conduction band VGP-BPS9/B formed on micro-, so that the use of various wavelengths of light possible.

Improve the quantum-dot superlattice type of conversion efficiency of the need to address the following issues: (1) reduce the thickness of the middle layer, and strengthen the integration between the quantum dots; (2) to enable the close arrangement of quantum dots; (3) stacking more layers . The University of Tsukuba to the middle layer thickness reduced to half of the past - 20nm, so that conversion sony vgp-bps9a/b battery efficiency from 3.7% to 8.54%. University of Tsukuba in the future goal is to 2020, the conversion efficiency increased to 40%.