title: Non-synchronization of lattice and carrier temperatures in light-emitting diodes.
abstract: Pulse implementation or switching-off (PISO) of electrical currents has become a common operation in junction-temperature (Tj) measurements for semiconductor devices since 2004. Here we have experimentally discovered a substantial discrepancy between Tj values with, and without, PISO (e.g., 36.8 °C versus 76.5 °C above the ambient temperature at 25.0 °C). Our research indicates that methods associated with PISO are flawed due to non-synchronization of lattice temperatures and carrier temperatures in transient states. To scrutinize this discrepancy, we propose a lattice-inertia thermal anchoring mechanism that (1) explains the cause of this discrepancy, (2) helps to develop a remedy to eliminate this discrepancy by identifying three transient phases, (3) has been applied to establishing an original, accurate, and noninvasive technique for light-emitting diodes to measure Tj in the absence of PISO. Our finding may pave the foundation for LED communities to further establish reliable junction-temperature measurements based on the identified mechanism.
authors.affiliation: Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, China.|Institute for Complex Adaptive Matter, University of California, Davis, CA 95616 USA.
authors.forename: Tienmo
authors.initials: T
authors.lastname: Shih
authors.affiliation: Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, China.|Leibniz Institute for Polymer Research, Dresden, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Merlitz
authors.affiliation: Shineraytek Optoelectronics Co., Shanghai 201300, China.
authors.forename: Richard Ru-Gin
authors.initials: RR
authors.lastname: Chang
authors.affiliation: Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen