The goal of this proposal is to enable us to equip with a new experimental system based on photoelectron spectroscopy in air (PESA), and scanning kelvin probe spectroscopy/surface photovoltage spectroscopy (S-KPS/SPVS). PESA is an emerging experimental technique allows to directly measuring the workfunction of various materials at standard conditions. This will allow us to rapidly screen the workfunction of a large number of new materials and rationally match them with the correct electrodes to achieve an optimal energy-level alignment. In addition, the unique capability to determine the energy levels under real operating conditions is very relevant for the device optimization. An important aspect from the blending of these techniques is the ability to understand how the bulk material- characterized individually- interacts with the substrate and the various contact layers of the complete device. Combining PESA with S-KPS/SPVS will uniquely enable a complete construction of the electronic band diagram between all the components of the solar cell devices. The new capability will allow deeper understanding a step-by-step deconvolution of the pair interactions among the various layers of the complex multijunction architecture of the devices. It will thus accelerate the path to successfully transition from the fundamental knowledge of electronic properties of the materials to the implementation of this knowledge to the actual solar cells.
|Effective start/end date||1/1/18 → 1/31/19|
- Office of Naval Research (N00014-18-1-2102 A00001)