Unravelling radiative energy transfer in solid-state lighting

Abstract

Today, a wide variety of organic and inorganic luminescent materials (e.g., phosphors, quantum dots, etc.) are being used for lighting and new materials (e.g., graphene, perovskite, etc.) are currently under investigation. However, the understanding of radiative energy transfer is limited, even though it is critical to understand and improve the performance levels of solid-state lighting devices. In this study, we derived a matrix approach that includes absorption, reabsorption, interabsorption and their iterative and combinatorial interactions for one and multiple types of fluorophores, which is simplified to an analytical matrix. This mathematical approach gives results that agree well with the measured spectral and efficiency characteristics of color-conversion light-emitting diodes. Moreover, it also provides a deep physical insight by uncovering the entire radiative interactions and their contribution to the output optical spectrum. The model is universal and applicable for all kinds of fluorophores.

Ultra‐Efficient and High‐Quality White Light‐Emitting Devices using Fluorescent Proteins in Aqueous Medium

“…To understand the achievable LED performance levels by fluorescent proteins, we performed optical simulations that consider all the photonic processes including absorption, reabsorption, inter‐absorption and their infinitely‐many possible interactions. [ 22 ] For white light generation, one strategy is the combination of green‐ and red‐emitting down conversion fluorescent materials with blue LEDs. We simulated the efficiency and the color quality of the generated white light with the combinations of the most efficient green‐emitting fluorescent proteins including Citrine, Sapphire, mHoneydew, eGFP and red‐emitting fluorescent proteins including mScarlet, mCherry, mPlum, and dTomato.…”

Efficient White LEDs Using Liquid-state Magic-sized CdSe Quantum Dots

“…Color rendering index, which shows the ability of rendering true colors of the illuminated objects, is an important feature of white light. While the optical density rises, the contribution by the QDs increased until the point with maximum luminous efficiency reached 45 and this boosted the color rendering index level up to 89 at the optical density of 0.068 (Fig. 4e).…”

On the unique solvability of radiative transfer equations with polarization

“…This equation was first derived using phenomenological arguments by Chandrasekhar [9], but has also been derived from the high-frequency limit of Maxwell's equations [14,22,25]. It is used in many applications, such as in medical imaging [2], neutron transport [8], atmospheric science [16], oceanography [1], pharmaceutical powders [6] or solid state lightning [21], see also [3,7].…”