Semiconductor nanostructure quantum ratchet for high efficiency solar cells

DOI: 10.1038/s42005-018-0007-6

Authors: Anthony Vaquero-Stainer (Imperial College London) , Megumi Yoshida (Imperial College London) , Nicholas P. Hylton (Imperial College London) , Andreas Pusch (Imperial College London) , Oliver Curtin (Imperial College London) , Mark Frogley (Diamond Light Source) , Thomas Wilson (Imperial College London) , Edmund Clarke (University of Sheffield) , Kenneth Kennedy (University of Sheffield) , Nicholas J. Ekins-Daukes (University of Sheffield) , Ortwin Hess (Imperial College London) , Chris C. Phillips (Imperial College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Communications Physics , VOL 1

State: Published (Approved)
Published: March 2018
Diamond Proposal Number(s): 12829

Abstract: Conventional solar cell efficiencies are capped by the ~31% Shockley–Queisser limit because, even with an optimally chosen bandgap, some red photons will go unabsorbed and the excess energy of the blue photons is wasted as heat. Here we demonstrate a “quantum ratchet” device that avoids this limitation by inserting a pair of linked states that form a metastable photoelectron trap in the bandgap. It is designed both to reduce non-radiative recombination, and to break the Shockley–Queisser limit by introducing an additional “sequential two photon absorption” (STPA) excitation channel across the bandgap. We realise the quantum ratchet concept with a semiconductor nanostructure. It raises the electron lifetime in the metastable trap by ~10^4, and gives a STPA channel that increases the photocurrent by a factor of ~50%. This result illustrates a new paradigm for designing ultra-efficient photovoltaic devices.

Journal Keywords: Solar Cell; Quantum Ratchet; Semiconductor; Photovoltaic; Quantum Well; Efficiency

Diamond Keywords: Photovoltaics; Semiconductors

Subject Areas: Physics, Energy, Materials


Instruments: B22-Multimode InfraRed imaging And Microspectroscopy

Added On: 08/03/2018 19:48

Documents:
s42005-018-0007-6.pdf

Discipline Tags:

Earth Sciences & Environment Sustainable Energy Systems Energy Physics Climate Change Energy Materials Materials Science Nanoscience/Nanotechnology

Technical Tags:

Spectroscopy Infrared Spectroscopy Synchtron-based Fourier Transform Infrared Spectroscopy (SR-FTIR)