Graphene-Semiconductor Quantum Well with Asymmetric Energy Gaps

Abstract

<p align="justify"> <span style="font-family:Verdana;font-size:12px;">Semiconductor solar cell (PV cell) has been widely used for generating solar electricity. However, the high cost and severe pollution limits its application. Recently the discovery of graphene may open a door to fabricate a novel solar cell with lower cost and more environmentally friendly. Our proposed solar cell device consists of a graphene strip and two semiconductor strips with different energy gaps attached to the two edges of the graphene strip on a flat plane. This structure is a two-dimensional quantum well. The energy bands of graphene can be described by a two-dimensional Dirac equation centered on hexagonal corners (Dirac points) of the honeycomb lattice Brillouin zone. The 2</span><span> </span><span style="font-family:Verdana;font-size:12px;">D Dirac equation has been solved numerically in this paper. The results indicate that the graphene quantum well possesses very dense quantum energy states which imply that quantum well of this type can absorb sun light with more different fre</span><span style="font-family:Verdana;font-size:12px;">quencies. If we use graphene quantum well to fabricate the photo voltaic cell, the efficiency of converting solar energy to electricity will be enhanced.</span> </p> <p> <span></span><span></span><span style="font-family:Verdana;"> </span> </p

Mid/far-infrared photo-detectors based on graphene asymmetric quantum wells

“…They proposed to use graphene quantum wells to fabricate photovoltaic cells. [36] In this case, the effect of the effective mass induced by the coupling with the substrate is not important and does not affect the energy spectrum. Questions that arise here are can this theoretical model be extended to low energy regimes, namely, mid-and far-infrared frequency regimes, and what is the physical quantity that proves this model can be applied to fabricate photovoltaic cells and mid/far-infrared photo-detectors.…”

“…Wang et al [36] presented a theoretical study of the quantum well based on graphene and narrow semiconductors with two different energy gaps. They proposed to use graphene quantum wells to fabricate photovoltaic cells.…”