Researchers analyze a heat engine based on a hot cavity connected via quantum wells to electronic reservoirs. They find that the device delivers a large power of about 0.18 W cm^−2 (1800 watts per square meter) for a temperature difference of 1 K, nearly doubling the power that can be extracted from a similar heat engine based on quantum dots. At the same time, the heat engine also has good efficiency albeit reduced from the quantum dot case. Due to the large level spacings that can be achieved in quantum wells, our proposal opens a route toward room-temperature applications of nanoscale heat engines.
It has 12 % of the Carnot efficiency. The large level spacings of narrow quantum wells pave the way for room-temperature applications. Furthermore, we find our device to be robust with respect to unavoidable well-width fluctuations.
Sunlight in space at the top of Earth’s atmosphere at a power of 1366 watts/m2 is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light. At ground level this decreases to about 1120–1000 watts/m2, and by energy fractions to 44% visible light, 3% ultraviolet (with the Sun at the zenith, but less at other angles), and the remainder infrared. Thus, sunlight’s composition at ground level, per square meter, with the sun at the zenith, is about 527 watts of infrared radiation, 445 watts of visible light, and 32 watts of ultraviolet radiation
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.