Photon Recycling in Semiconductor Thin Films and Devices

Abstract

Photon recycling (PR) plays an important role in the study of semiconductor materials and impacts the properties of their optoelectronic applications. However, PR has not been investigated comprehensively and it has not been demonstrated experimentally in many different kinds of semiconductor materials and devices. In this review paper, first, the authors introduce the background of PR and describe how this phenomenon was originally identified in semiconductors. Then, the theory and modelling of PR is reviewed and some of the important parameters that are used to quantify PR are highlighted. Next, a variety of the methods used to achieve and characterize PR in materials and devices are discussed. Examples of how the performance parameters of different types of optoelectronic devices are affected by PR are described. Finally, a summary of the roles of PR in semiconductor materials and devices and an outlook on how PR can be used to solve existing problems and challenges in the field of optoelectronics are provided. From this review, it is apparent that PR can have a positive impact on optoelectronic device performance, and that further in‐depth theoretical and experimental studies are needed to rigorously demonstrate the advantages and importance of PR.

A small-molecule-templated nanostructure back electrode for enhanced light absorption and photocurrent in perovskite quantum dot photovoltaics

“…It is well-known that the PV performance of solar cells can be improved by recycling the light transmitted from the PV absorber by introducing nanostructures into the back-side electrodes. 43 Thus, we carried out nanoimprint lithography on the small-molecule spiro-OMeTAD HTL using a nanostructured poly(dimethylsiloxane) (PDMS) mold to fabricate back-side nanostructured CsPbI 3 -PQD solar cells (see details in the Experimental section). We first used a PDMS mold having a 1D line-grating nanostructure with a height of ∼40 nm and a period of ∼420 nm (P4) and performed nanoimprint lithography on the spiro-OMeTAD layers, which were spin-coated for various durations (Fig.…”

Directional emission of white light via selective amplification of photon recycling and Bayesian optimization of multi-layer thin films

“…Hereby, an effect called ray ping pong is identified to be responsible for the improved directional emission of white light. Related effects like photon recycling 43 were studied in previous work for solar GaAs cells 44 – 46 , perovskite LEDs 47 or thin films themselves 48 . In our work, depending on their wavelength and incident angle, the rays are considered to be partially trapped in the LED package by an MLTF, enforcing interactions between rays and LED package materials like scattering, (re-)absorbtion, (re-)emission or non-radiative effects.…”

Playing Ping Pong With Light: Directional Emission of White Light

“…Hereby, an effect called ray ping pong is identified to be responsible for the improved directional emission of white light. Related effects like photon recycling 40 were studied in previous work for solar GaAs cells [41][42][43] , perovskite LEDs 44 or thin films themselves 45 . In our work, depending on their wavelength and incident angle, the rays are considered to be partially trapped in the LED package by an MLTF, enforcing interactions between rays and LED package materials like scattering, (re-)absorbtion, (re-)emission or non-radiative effects.…”