+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
News Article

Solar power for unmanned automonous vehicles

A quantum-dot-based thin-film approach enables development of light, powerful, and flexible photovoltaic cells.

In battlefield environments, the longevity of many electronic sensors such as those found in unmanned aerial vehicles relies on their ability to replenish their energy reserves. Solar radiation is a major potential source of energy and photovoltaic cells offer a promising way to harvest that energy. One possible application is to use the relatively large surface of a microautonomous bat's wings, provided the cells are flexible enough for the wings to flap. In addition, for small platforms with constrained size and weight limitations, it is highly desirable to increase the power density (W/g) substantially from the 0.13W/g that is currently commercially available.


Such cells are currently made using organic cells, amorphous silicon, and pliable arrays of rigid solar cells. Organic solar cells possess benefits in being highly flexible and cheap in production. However, they also have a very short lifetime and low efficiency (~5%). Amorphous silicon is also pliable and inexpensive, but it also suffers from low efficiency as well as low versatility for circuit design. We have developed a new thin-film, pixellated microchip solar-cell-array approach based on quantum dots (QDs) using a dots-in-a-well (DWELL) structure,1 which is pliable, light, and efficient. Our new method of making the array does not result in decreasing efficiency as the flexibility improves. Arrays of these microcells are as efficient as conventional solar panels.


A QD is a semiconductor whose excitons are confined in all three spatial dimensions. As a result, they have properties that are between those of bulk semiconductors and discrete molecules. Figure 1 shows the DWELL structure, where the indium arsenide (InAs) QDs are fully embedded in the gallium InAs quantum wells. Our group has successfully grown DWELL structures since 1999,1 and applied them in various QD devices with state-of-the-art performance, such as low-threshold current-density diode lasers2 and high-responsivity, long-wave IR detectors.



Source: To read full article http://spie.org/x39218.xml?highlight=x2358&ArticleID=x39218

Connecting the Compound Semiconductor Industry

The 13th CS International conference builds on the strengths of its predecessors, with around 40 leaders from industry and academia delivering presentations that fall within five key themes: Ultrafast Communication; Making Headway with the MicroLED; Taking the Power from Silicon, New Vectors for the VCSEL, and Ultra-wide Bandgap Devices.

Delegates attending these sessions will gain insight into device technology, find out about the current status and the roadmap for the compound semiconductor industry, and discover the latest advances in tools and processes that will drive up fab yields and throughputs.

To discover our sponsorship and exhibition opportunities, contact us at:

Email: info@csinternational.net
Phone: +44 (0)24 7671 8970

To register your place as a delegate, visit: https://csinternational.net/register

Search the news archive

To close this popup you can press escape or click the close icon.
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.

Please subscribe me to:


You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: