The paper entitled "Optimal ITO transparent conductive layers for InGaN-based amber/red light-emitting diodes" reports the optimal double ITO layers on InGaN-based amber and red LEDs enhanced light output power by 15.6% and 13.0%, respectively, compared to those using ITO layers by e-beam evaporation.
Optics Express 28, 12311 (2020). DOI: 10.1364/OE.389725