Thermal droop in InGaN-based LEDs: physical origin and dependence on material properties
| Autor: | Stefano Dominici, Gaudenzio Meneghesso, M. Mandurrino, Roland Zeisel, Enrico Zanoni, C. De Santi, Francesco Bertazzi, Bastian Galler, Michele Goano, Nicola Trivellin, Matteo Meneghini, M. La Grassa, Berthold Hahn |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Phonon Thermionic emission Gallium nitride 02 engineering and technology Electron blocking layer Light emitting diode Indium gallium nitride 01 natural sciences Thermal droop chemistry.chemical_compound 0103 physical sciences Voltage droop Carrier escape Shockley-Read-Hall recombination Quantum well Quantum tunnelling Diode 010302 applied physics business.industry 021001 nanoscience & nanotechnology chemistry Optoelectronics 0210 nano-technology business |
| Popis: | The thermal droop (reduction of the optical power when the temperature is increased) is a phenomenon that strongly limits the efficiency of InGaN-based light-emitting diodes. In this paper we analyze the role of Shockley-Read-Hall (SRH) recombination and of the electron blocking layer (EBL) in the process by using numerical simulations and literature data. The benefic impact of EBL suggests that carrier escape from the quantum wells gives a significant contribution to the thermal droop, therefore we review some of the mechanisms described in the literature (thermionic emission, phonon-assisted tunneling, thermionic trap-assisted tunneling). Since no formulation is able to fit the behavior of the measured SQW devices, we develop a new model based on two phonon-assisted tunneling steps through a defective state, extended in order to take into account zero-field emission. By using experimental data, material constants from the literature and only two fitting parameters the model is able to reproduce the experimental behavior. |
| Databáze: | OpenAIRE |
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