Fig. 3: Quantum efficiency and photocurrent.
From: Two-photon photocurrent in InGaN/GaN nanowire intermediate band solar cells
a Schematic of the quantum efficiency and reflectivity experimental setup including the laser light bias. b Microscope image of the solar cell with the tunable beam (green) and near-infrared light-bias beam (gray) spots. c Energy levels and transition energies showing the transitions enabled by the tunable beam and the 850 nm light bias. d Short-circuit quantum efficiency at room temperature and 78 K with and without a 200 W/cm2 light bias in a cryostat. e Sub-bandgap (>370 nm) photocurrent as a function of temperature without light bias, calculated from quantum efficiency measurements. Lines are guides to the eye. Error bars indicate estimated errors in photocurrent (±5%). f Calculated short-circuit current from the quantum efficiency under AM1.5D illumination as a function of light-bias intensity at 295 K without a cryostat.
