The innovation engine for new materials

Self-healing Phosphor: New Paradigm for High-power LED Lighting Application

Seminar Group: 


Prof. Won Bin Im


School of Materials Science and Engineering, and Optoelectronics Convergence Research Center
Chonnam National University, Republic of Korea


Friday, March 23, 2018 - 11:00am


MRL Room 2053


Prof. Ram Seshadri

Phosphor-converted white light-emitting diodes (pc-WLEDs) are the efficient light source that has multifarious applications in lighting, high-tech displays, and electronic devices. One of the biggest challenges of pc-WLEDs is the thermal quenching (TQ), in which phosphor suffers from emission loss with increasing temperature during high- power LED operation and is an inevitable drawback for any existing phosphor. Here, we present robust and none-TQ WLEDs using various strategies to overcome the TQ and efficiency decrease by means of (1) phosphor-plate with high thermal conductivity by graphene-wrapping, (2) solid-solution phosphors with structural information by diffraction techniques, and (3) a zero-thermal-quenching phosphor. In particular, for the first time, a new blue-emitting phosphor that doesn’t exhibit TQ revealing zero-emission loss even up to 250C. This phenomena of a zero-thermal quenching, denoted as self- healing phosphor, portrays the ability of phosphor in resurrecting the emission loss and sustaining the luminescence with increasing temperature. This finding would initiate the exploration of many self-healing phosphors with zero-thermal quenching for high-power LED applications.