Design and comparative study of lateral and vertical LEDs with graphene as current spreading layer

• We observe better performance in lateral LED with graphene CSL compared to ITO CSL.
• We compare effect of graphene CSL on performance of lateral and vertical LED.
• With graphene CSL, VLED show 62% lower series resistance than LLED.
• VLED with graphene CSL show 17/16% higher light output power/wall plug efficiency.
• We may conclude that VLED with graphene CSL is a better alternative to LLED.

This study analyzes the current spreading effect of graphene on lateral and vertical light emitting diodes (LEDs). We observe an improvement in uniformity of current distribution, light output power and wall-plug efficiency in lateral LEDs (L-LEDs) with graphene current spreading layer (CSL) as compared to those with indium tin oxide (ITO) CSL. From the results we conclude that graphene CSL may be better alternative to ITO CSL. We further carried out a comparative study of lateral and vertical LEDs with graphene CSL. We observe 17% higher light output power, 16% higher wall-plug efficiency and 62% lower series resistance in the case of V-LEDs with graphene CSL when compared to that of L-LEDs with a graphene CSL. Reasons behind these results have been discussed.