Nanostructured Compound Semiconductor Solar Cells

太阳能电池的效率与成本比决定了太阳能发电的价格，从而影响了社会对太阳能电池的吸收速度。目前可用的低成本选项具有低效率和稳定性问题。另一方面，稳定高效的产品价格昂贵。现在需要一种稳定、低成本和高效率的产品，以鼓励增加可再生能源的发电量。更有吸引力的是一种灵活且重量轻的选择，可以将太阳能电池直接集成到建筑物中，并加速可再生能源的使用。该项目旨在展示这一急需的产品，以填补当前太阳能电池市场的差距。化合物半导体是固有的稳定材料，并保持着目前在1太阳，AM1.5G照明下最高效率的单结太阳能电池的记录。然而，在传统的基于晶片的架构中使用的大量半导体材料极大地增加了与这些器件相关联的重量和成本，并且使得诸如灵活性的功能不可想象。该项目将调用化合物半导体纳米结构中的非传统光吸收特性来制造更便宜的太阳能电池，仅使用基于晶片的架构中使用的一小部分材料，而不会影响效率。纳米结构化使得能够控制光-半导体相互作用。通过适当的设计，光可以被有效地定位/捕获在仅几纳米厚的吸收层中，直到它被完全吸收。纳米结构的化合物半导体吸收体可以直接在便宜的柔性衬底上生长，或者在半导体晶片上生长之后转移到柔性衬底上，使得能够重新使用晶片进行更多的生长。这种方法将使设备灵活且具有成本效益。

The efficiency to cost ratio of solar cells determines the price of solar generated electricity, and hence impacts the speed of up-take of solar cells by the society. The low-cost options currently available have low efficiencies and stability issues. On the other hand, stable and high efficiency products are expensive. A stable, low cost and high efficiency product is now required to encourage increased energy generation from renewable sources. Even more appealing is a flexible and light weight option that will enable integration of solar cells directly into buildings and accelerate the uptake of renewable energy sources. This project aims to demonstrate this much-needed product to fill-in the gap in the current solar cell market.Compound semiconductors are inherently stable materials and hold the current record for the highest efficiency single junction solar cells under 1 Sun, AM1.5G illumination. However, the large volume of semiconductor material used in the conventional, wafer based architecture enormously increases the weight and costs associated with these devices, and makes functionalities like flexibility unthinkable. This project will invoke non-conventional light absorption characteristics in compound semiconductor nanostructures to fabricate cheaper solar cells that use just a fraction of material used in the wafer based architecture, without compromising the efficiency. Nanostructuring enables control of the light-semiconductor interaction. Through proper design, light can be effectively localised/trapped in an absorber layer only a few nanometers thick until it is completely absorbed. The nanostructured compound semiconductor absorber can be grown directly on a cheap, flexible substrate or transferred to a flexible substrate, following growth on semiconductor wafers, enabling re-use the wafer for many more growths. This approach will make the devices flexible and cost-effective.