PROJECT TITLE :

Photocurrent Generation by Two-Step Photon Absorption With Quantum-Well Superlattice Cell

ABSTRACT:

We have observed photocurrent thanks to two-step photon absorption using an InGaAs/GaAsP strain-balanced quantum-well (QW) superlattice cell, with barrier thickness of 3 nm. Upon infrared irradiation with a filtered air mass 1.five lightweight supply (λ > 1.4 μm), quantum potency was increased by zero.8% at the wavelength vary similar to the absorption of the quantum wells. No efficiency enhancement was observed either for a typical QW solar cell with thick (11 nm) barriers or for a GaAs pin cell, suggesting that efficient separation of photogenerated electrons and holes in the superlattice is important for this achievement of 2-step photon absorption. The quantum efficiency of such 2-step photocurrent generation will be enhanced by specific tailoring of a superlattice layer structure, by which the QW superlattice can be a attainable active region for an intermediate-band solar cell.