Nanoscale light emitting diodes or nanolasers are of technological interest in miniaturized applications such as low size weight and power high-definition displays or on-chip electro-optical platforms for sensing or communication. Although semiconductor micro- and nanoscale diodes have been formed with a broad range of compositions using top-down and bottom-up growth methods, the scalable electrical injection to individual diodes remains to be a challenge as dimensions of light emitting diodes are reduced below sub-micron. 1,2 More challenging is powering up series of such nanodevices in a scalable style. This is because the popular architectures currently used rely on free-standing structures or cavities that makes it difficult their individual interfacing with electrical contacts. To address this issue, we developed an architecture that forms nanodiodes or cavities that are formed in-plane of the surface. These nanodiodes are one-dimensional nanocrystals grown using lateral epitaxy on surfaces 3 such as GaN to form elongated semiconductor heterojunctions. Here, we report the first generation of a linear array of nanoscale UV light sources on a-chip. Systematic output power density measurements show that each individual light source intensity can be tuned depending on the number of used nanodiodes. For instance, a light source containing only 8 nanodiodes can generate 720 W/cm 2 power at a 10 mA load, which is 7 times brighter than a commercial thin film LED. In this presentation we describe the electronic structure of these heterojunctions as well as their light generation performance. An outlook will also be provided for their applications in on-chip chemical and biological threat detection.