Size-Dependent Electroluminescence and Current-Voltage Measurements of Blue InGaN/GaN µLEDs down to the Submicron Scale
Stefan Wolter,
Hendrik Spende,
Jan Gülink,
Jana Hartmann,
Hergo-Heinrich Wehmann,
Andreas Waag,
Andreas Lex,
Adrian Avramescu,
Hans-Jürgen Lugauer,
Norwin von Malm,
Jean-Jacques Drolet,
Martin Strassburg
Affiliations
Stefan Wolter
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Hendrik Spende
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Jan Gülink
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Jana Hartmann
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Hergo-Heinrich Wehmann
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Andreas Waag
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Andreas Lex
Epitaxy Competence Center (ec<sup>2</sup>), Laboratory of Emerging Nanometrology (LENA) and Institute of Semiconductor Technology (IHT), Technische Universität Braunschweig, 38106 Braunschweig, Germany
Besides high-power light-emitting diodes (LEDs) with dimensions in the range of mm, micro-LEDs (μLEDs) are increasingly gaining interest today, motivated by the future applications of μLEDs in augmented reality displays or for nanometrology and sensor technology. A key aspect of this miniaturization is the influence of the structure size on the electrical and optical properties of μLEDs. Thus, in this article, investigations of the size dependence of the electro-optical properties of μLEDs, with diameters in the range of 20 to 0.65 μm, by current–voltage and electroluminescence measurements are described. The measurements indicated that with decreasing size leakage currents in the forward direction decrease. To take advantage of these benefits, the surface has to be treated properly, as otherwise sidewall damages induced by dry etching will impair the optical properties. A possible countermeasure is surface treatment with a potassium hydroxide based solution that can reduce such defects.
