Light-Induced Interfacial Phenomena in Atomically Thin 2D van der Waals Material Hybrids and Heterojunctions

Abstract

Atomically thin 2D van der Waals (2D-vDW) materials have attracted significant attention for optoelectronic applications in photodetectors, photovoltaics, and quantum information science. Their atomically thin thickness, however, renders them poor absorbers. Hybrid structures of 2D-vDW materials assembled with other semiconducting materials, such as quantum dots, nanowires, polymers, other 2D-vDW materials, or 3D bulk materials, have provided an elegant way to increase light harvesting and carrier generation via interfacial charge and energy transfer interactions.Here we present recent examples focused on the characterization of interfacial charge transfer and energy transfer in 2D-vDW hybrids and heterostructures and methods to modulate and control these processes through band gap engineering, morphology engineering, and external factors. Finally, we discuss potential future directions of research, including scalability from micron-sized flake-based devices to wafer size for commercial deployment, issues with long-term stability and performance, and the ability to extend the spectral range of these 2D hybrids.

A new ultrafast energy funneling material harvests three times more diffusive solar energy for GaInP photovoltaics

“…For photovoltaic applications, this concept can only work if the light-harvesting concentrators have efficiencies of nearly 100% as otherwise the higher efficiencies of expensive high-performance solar cells are quickly outweighed ( 12 , 13 ). Therefore, researchers currently try to find systems that reach close to light-harvesting efficiencies of 100% ( 14 – 23 ). Conventional light-concentrator concepts consist of one-pigment composites in waveguiding materials such as poly(methyl methacrylate) and have several intrinsic loss mechanisms that quickly reduce their light-harvesting efficiency below 50%.…”

Optical simulation of ultimate performance enhancement in ultrathin Si solar cells by semiconductor nanocrystal energy transfer sensitization

“…Overall, our modeling results identified a range of device subcomponent layer thickness combinations optimal for maximizing for a given thickness of ultrathin Si, providing J SC useful design guidelines towards developing highly effective ETenhanced ultrathin Si solar cells. Considering a weak light absorption is a common issue in many ultrathin materials such as two-dimensional Van der Waals semiconductors 19 , the general theoretical framework encompassing both TMM and ET calculations demonstrated in this study should find utility beyond ultrathin Si solar cells. The framework we have presented can precisely assess and analyze diverse device geometries and configurations with large parameter spaces in advanced ET-based ultrathin semiconductor optoelectronic devices.…”

“…10 The experiment revealed a unique dual functionality of the NCs: Not only did they improve the optical coupling of incident light into the active ultrathin Si layer by acting as an anti-reflective coating, but they also improved light harvesting via direct energy transfer (ET) from the NCs into the Si layer through radiative and nonradiative ET processes, consistent to what has been originally proposed and identified by the Malko group in a series of reports. 11,12 A similar ET-based NC sensitization scheme has been recently used to improve the light absorption in a Si-based photodetector 13 , organicinorganic hybrid perovskites 14 , and various two-dimensional semiconductors [15][16][17][18][19] .…”

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