US Patent:
20190036473, Jan 31, 2019
Inventors:
- Adelphi MD, US
Andrei V. Sergeyev - Silver Spring MD, US
John W. Little - Ellicott City MD, US
International Classification:
H02S 10/30
H01L 31/054
H01L 31/056
G02B 5/28
G02B 1/115
Abstract:
Embodiments of the invention generally relates to photovoltaic, thermophotovoltaic, and laser power beaming devices which convert solar light, thermal radiation, or laser radiation into electric power. Said devices have a reflective interference “greenhouse” filter placed in front of a semiconductor cell and a reflective mirror on the back of the cell. The front filter is transparent for high energy (short wavelength) photons, but traps low energy (long wavelength) photons emitted by photocarriers accumulated near the semiconductor bandgap. In the optimized PV device, the chemical potential of photoelectrons near semiconductor bandgap exceeds the chemical potential of photoelectrons above the photonic bandgap established by the filter (i.e., the device is in chemical nonequilibrium). The greenhouse filter reduces the emission losses, decreases the semiconductor cell thickness, and provides PV conversion with reduced nonradiative losses. Said device converts radiative energy into electricity in a more efficient way than conventional cells.