Influence of photo-generated carriers on current spreading in double diode structures for electroluminescent cooling
Loading...
Access rights
© 2018 IOP Publishing.
Journal Title
Journal ISSN
Volume Title
School of Science |
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.
Date
2018
Major/Subject
Mcode
Degree programme
Language
en
Pages
Series
Abstract
Current crowding close to electrical contacts is a common challenge in all optoelectronic devices containing thin current spreading layers (CSLs). We analyze the effects of current spreading on the operation of the so-called double diode structure (DDS), consisting of a light emitting diode (LED) and a photodiode (PD) fabricated within the same epitaxial growth process, and providing an attractive platform for studying electroluminescent (EL) cooling under high bias conditions. We show that current spreading in the common n-type layer between the LED and the PD can be dramatically improved by the strong optical coupling between the diodes, as the coupling enables a photo-generated current through the PD. This reduces the current in the DDS CSL and enables studying EL cooling using structures that are not limited by the conventional light extraction challenges encountered in normal LEDs. The current spreading in the structures is studied using optical imaging techniques, electrical measurements, simulations, as well as simple equivalent circuit models developed for this purpose. The improved current spreading leads further to a mutual dependence with the coupling efficiency, which is expected to facilitate the process of optimizing the DDS. We also report a new improved value of 63% for the DDS coupling quantum efficiency (CQE).Description
Keywords
electroluminescent cooling, quantum efficiency, radiative and non-radiative recombination, III-V semiconductors, double diode structures, current spreading
Other note
Citation
Radevici, Ivan & Tiira, Jonna & Sadi, Toufik & Oksanen, Jani. 2018. Influence of photo-generated carriers on current spreading in double diode structures for electroluminescent cooling. ISSN 0268-1242 (printed). DOI: 10.1088/1361-6641/aab6c3.
