About this Research Topic
The emerging generation of thin film photovoltaics based on perovskites, organic semiconductors, and colloidal quantum dots, have strong potential to deliver a transformative reduction in the cost of generating electricity directly from sunlight, and are well suited to a range of applications in buildings integration and transportation for which conventional flat plate photovoltaics are poorly suited. However, achieving the full cost advantage and breadth of potential applications depends critically on the properties of, and bill of materials for, the electrode that couples light into the device: the window electrode. A window electrode ideally matched to the needs of these classes of emerging photovoltaics need to be based on inexpensive and non-toxic raw materials, that can be processed using scalable, low cost deposition methods, such as roll-to-roll vacuum evaporation, printing or spray coating, and be compatible with flexible substrates. Additionally, the electrode sheet resistance must be less than 10 ohms per square and the absolute far-field transparency must exceed 80%. This demanding list of requirements rule out the use of conventional conducting oxide electrodes, including the indium-tin oxide coated glass, which is the leading window electrode material for display applications.
In recent years window electrodes based on metal nanowires and optically thin metal films on flexible substrates have begun to emerge as truly viable platforms for this application space, already exceeding the performance of indium-tin oxide on plastic substrates. To date, silver has been the metal of choice because it offers the highest electrical conductivity and lowest optical losses, although its relatively high cost has motivated researchers to explore other lower cost metals and alloys. This Research Topic will focus on materials science and engineering advances in this critically important, highly interdisciplinary and fertile area of research. Original research papers and focused reviews are welcome in the following areas:
1. Chemical and physical approaches to stabilising optically thin films of metal and metal nano-wires towards oxidation in air and the corrosive decomposition products in perovskite solar cells, without electrical isolation;
2. Advances in the deposition processes and methods for the fabrication of metal window electrodes;
3. Novel window electrode designs and architectures;
4. Strategies for patterning optically thin metals to achieve the target optical and electrical properties;
5. Plasmon-active metal window electrodes.