P2V visits to manufacture III-V test structures in Korea

The output voltage in a solar cell is limited by the semiconducting material the cell is made of. This because the voltage is related to the so-called band gap of the material, which in conventional silicon (Si) solar cells results in an output voltage of typically ~0.73V. The concept proposed in the P2V project, however, de-couples the output voltage from the material properties, so that one can design the output voltage to the load or device of interest, rather than vice versa. This will be done by using polarization effects that occur in several types of materials that can be used in solar cells. The output voltage in a solar cell is limited by the semiconducting material the cell is made of. This because the voltage is related to the so-called band gap of the material, which in conventional silicon (Si) solar cells results in an output voltage of typically ~0.73V. The concept proposed in the P2V project, however, de-couples the output voltage from the material properties, so that one can design the output voltage to the load or device of interest, rather than vice versa. This will be done by using polarization effects that occur in several types of materials that can be used in solar cells. The present scholarship, P2Vvisit, a travel grant related to the P2V project and intended for traveling/exchange and initiating collaboration with Dr Jong Hyeob Baek at Korean Photonics Technology Institute (KOPTI) and Prof. In-Hwan Lee at Chonbuk National University (CBNU). The exchange visit lasted in total of about 6 months, divided into two visits. The first visit was carried out in autumn 2017 (from 7/Aug/2017 till 2/Oct/2017 ? with additional funding from UiO:Energy), and the next in winter 2017/spring 2018 (from 16/Dec/2017 till 01/05/2018 ? with additional funding from UiO- young research talent). In the P2V project, we need to make two different crystal structures of a semiconducting material, one with non-centrosymmetric crystal structure exhibiting polar nature and other with non-polar characteristics, in a multi-quantum well structure. This can be done with cubic-CdO(non-polar) and wurtzite-ZnO (polar), which was our initial investigations in the P2V project, or using two different phases of gallium nitride (GaN). At KOPTI, they are experts in fabrication of the wurtzite (WZ) structure of GaN, which are commonly used for light emitting devices (LEDs). In the first visit, focus was therefore on making the cubic phase of GaN using metal-organic vapor phase epitaxy (MOVPE), which is the growth technique used to make wurtzite GaN. At the end of the first stay this was achieved, as verified by Photoluminescence (PL) and Transmission electron microscopy (TEM) analysis. The next visit therefore focused on understanding and optimizing the growth conditions, and fabricating layered structures of alternating wurtzite and cubic phases.

Polarization photovoltaic (P2V) is a part of the ENERGIX project portfolio from its recently lunched "new concept" Calls. Via the present proposal we apply for travel funds in order to implement our P2V idea in new materials that can be synthesized overseas, specifically in Korea and characterized in Norway. Our partners are among the leading experts in III-V-based materials and we have documented previous interactions illustrating the feasibility of the effort. In total 6-month visit to Korea is foreseen during 2016-2017. It is expected that this collaboration will contribute to the successfulness of the P2V project, i.e will be relevant to the ENERGIX work programme. It also will broaden our scientific horizons via exploration of new materials in collaboration with world class research and innovation environment in Korea. As such, this effort will obviously enhance the internationalization of the research and research training in Norway. In a broader perspective, the present project inherits all expected impacts as being formulated in the P2V project, including scientific, innovation, environmental, and society related expected outcomes. Notably, there is a synchronized application for Korean researchers to visit Norway enhancing the synergy of collaboration.