US 2015/0318429 A1 · ACTIVE SOLAR CELL AND METHOD OF MANUFACTURE

Abstract

Methods for improving the efficiency of solar cells, and a solar cell thereof. One aspect involves a solar cell with a semiconductor layer (11, 12, 13, 14, 15, 16, 17) with a natural band gap NB (NB2, NB3, NB4, NB5, NB6, NB7). This semiconductor layer also has at least one electrode (100, 101, 110, 111, 120, 121) designed to produce an ambient voltage V (V1, V2, V3, V4, V5, V6, V7) into the layer. The incoming photons therefore experience a modified NB−V=B band gap (B1, B2, B3, B4, B5, B6, B7), referred here to as the apparent band gap. Photons with E>B1 will be absorbed into the band gap B, and the electron in the semiconductor valence band will get excited onto the conduction band thus resulting in photocurrent. The ability to tune the apparent band gap B provides an enormous strength to optimize the incoming photon collection.

Claims4

Dependent claims

A method for operating a solar cell, comprising at least two semiconductor layers, comprising:

raw solar spectrum hitting first semiconductor layer with band gap NB1 (600);
passing photons with energy E<NB1 through the first semiconductor layer (620);
absorbing photons with energy E>NB1 and converting to photocurrent, secondary photons left with E−NB1 remain from the absorbed photons (630);
photons with energy E<NB1 and secondary photons with energy equal to E−NB1 are incident on a second semiconductor layer with band gap NB2 (640);
determining a secondary photon population spectrum left by an incident solar spectrum through the first semiconductor layer from spectrometer measurements;
and
optimizing combined fit of semiconductor layer responses to the incoming solar spectrum and emerging spectra through each semiconductor layer to maximize collected photocurrent or power.

4 more elements

Dependencies are inferred from the claim text.

Active solar cell and method of manufacture

Life of this patent

Active solar cell and method of manufacture

Life of this patent

Abstract

Claims4