Resonant Energy Transfer from Organics to Quantum Dots and Carrier Multiplication

TL;DR

This paper discusses how resonant energy transfer in hybrid organic/inorganic structures can significantly enhance free carrier generation, potentially improving solar cell efficiency through nanocrystal-based carrier multiplication.

Contribution

It introduces the idea that resonant energy transfer from organics to quantum dots can drastically increase carrier multiplication, advancing photovoltaic technology.

Findings

Resonant energy transfer can increase carrier generation tens of times.

Hybrid structures with small-gap nanocrystals enhance solar conversion.

Organic layers act as light concentrators in these structures.

Abstract

It was shown in the recent experiments that the hybrid organic/inorganic resonant structures can provide a flexible materials platform aimed at the design of novel light emitting devices. The applications of hybrid structures for photovoltaic solar cell can also be useful. We pay attention in this note that the resonant energy transfer in hybrid structure from the organic thin layer to the semiconductor nanostructures can drastically increase the intensity of the free carrier generation. To demonstrate this idea we use the results of recently published paper by Zhang et al., Nature Nanotechnology 2, 555 (2007), demonstrating the highly efficient resonance energy transfer from J-aggregates layer to semiconductor nanocrystals. It is known that the semiconductor nanocrystals with small energy gap represent a promising route to increased solar conversion in single--junction photovoltaic cells. We argue that the using of nanocrystals with small energy gap in the hybrid organic/inorganic structures similar to created by Zhang et al. can increase tens times the total intensity of carrier multiplication. The organic part in such hybrid structures will play a role of the peculiar organic concentrator of the light energy.