Paper TF+EN-MoM9
Performance of ALD Oxide Films in Polarized Infrared Power Generation

Monday, October 28, 2013, 11:00 am, Room 104 A

Currently there is a large demand for alternative sources of clean, inexpensive, renewable energy. Solar radiation is very promising in this context. While the visible and near infrared (NIR) portions of the solar radiation spectrum are receiving much attention, thus far little work has been devoted to harvesting and transforming the middle and far (MIR and FIR) regions of the infrared (IR) portion of the spectrum. Here we describe the principle of IR power generation, which transforms IR radiation into electricity using a power generator (PG). While the physical mechanism of IR power generation is not yet fully understood, there is a clear indication that the termination of the external surface of the hot junction of the PG can be used to tune the electricity that is produced. The hot junction of the PG is usually made of a thin copper substrate with about a 1 mm thick alumina ceramic material on the external surface exposed to the IR radiation which absorbs on average about 60 % of the incident IR energy [1]. By terminating the hot junction with a spectrally black surface (emissivity approaching 1.0), this percentage can be greatly enhanced. Also, radiative polaritons [2] in thin alumina films on metallic, semiconducting, and insulating coatings further contribute to absorbing the IR radiation [1]. Thus, a 250 nm thick Al₂O₃ film deposited using atomic layer deposition (ALD) on Al foil placed on the hot junction of the PG can tune the response of IR power generation [3]. The behavior of voltage difference as a function of time measured with non-polarized IR radiation at variable incidence angle q₀ to the normal of the hot junction of the PG was recently published [3]. The presentation here will summarize the first results of the polarized IR power generation obtained from the 250 nm thick ALD Al₂O₃ films on Al foil. Finally, the future technological and scientific challenges for IR power generation using PGs, such as the development of Nighttime Solar Cells® [4] and the discovery of the physical mechanism, will be briefly summarized.

[1] A.J. Vincent-Johnson, K.A. Vasquez, G. Scarel, J.S. Hammonds, and M. Francoeur, Appl. Spectrosc. 66, 188-197 (2012).

[2] A.J. Vincent-Johnson, Y. Schwab, H.S. Mann, M. Francoeur, J.S. Hammonds, and G. Scarel, J. Phys: Condens. Matter 25, 035901 (2013).

[3] A.J. Vincent-Johnson, K.A. Vasquez, J.E. Bridstrup, A.E. Masters, X. Hu, and G. Scarel, Appl. Phys. Lett. 99, 131901 1-3 (2011).