Monolayer two-dimensional (2D) materials hold promise for solar photovoltaics. This work investigated whether the 100% absorption could be achieved by 2D material solar absorbers with simple planar structure. The absorber was designed to consist of a 2D material film on top of a transparent layer coated on metallic substrate. The two-dimensional condition for perfect absorption can be satisfied by adjusting the transparent layer thickness and the incident angle. The results for the MoS2 and graphene absorbers show that there always exist a pair of transparent layer thickness value and incident angle value at which these absorbers achieve the 100% absorption. In addition, these absorbers can be easily fabricated, and thus they pave the way to efficient 2D material photovoltaic devices.
WANG Lin
,
LIU Dong
,
LI Qiang
. Ultrathin planar solar absorbers using monolayer two-dimensional materials[J]. Journal of University of Chinese Academy of Sciences, 2018
, 35(2)
: 270
-274
.
DOI: 10.7523/j.issn.2095-6134.2018.02.018
[1] Bernardi M, Palummo M, Grossman J C. Extraordinary sunlight absorption and one nanometer thick photovoltaics using two-dimensional monolayer materials[J]. Nano Letters, 2013, 13(8):3664-3670.
[2] Mak K F, Lee C, Hone J, et al. Atomically thin MoS2:a new direct-gap semiconductor[J]. Physical Review Letters, 2010, 105(13):136805.
[3] Furchi M M, Pospischil A, Libisch F, et al. Photovoltaic effect in an electrically tunable van der Waals heterojunction[J]. Nano Letters, 2014, 14(8):4785-4791.
[4] 刘东, 于海童, 杨震, 等. 全碳太阳能热光伏系统. 工程热物理学报[J], 2015, 36(4):698-702.
[5] Zhao B, Zhang Z M. Strong plasmonic coupling between graphene ribbon array and metal gratings[J]. ACS Photonics, 2015, 2(11):1611-1618.
[6] Piper J R, Fan S H. Broadband absorption enhancement in solar cells with an atomically thin active layer[J]. ACS Photonics, 2016, 3(4):571-577.
[7] Kats M A, Blanchard R, Genevet P, et al. Nanometre optical coatings based on strong interference effects in highly absorbing media[J]. Nature Materials, 2013, 12(1):20-24.
[8] Long Y, Su R, Wang Q, et al. Deducing critical coupling condition to achieve perfect absorption for thin-film absorbers and identifying key characteristics of absorbing materials needed for perfect absorption[J]. Applied Physcis Letters, 2014, 104(9):091109.
[9] Kats M A, Byrnes S, Blanchard R, et al. Enhancement of absorption and color contrast in ultra-thin highly absorbing optical coatings[J]. Applied Physcis Letters, 2013, 103(10):101104.
[10] Liu D, Yu H T, Yang Z, et al. Ultrathin planar broadband absorber through effective medium design[J]. Nano Research, 2016, 9(8):2354-2363.
[11] Palik E D. Handbook of optical constants of solids I[M]. New York:Academic Press, 1985:350-357.
[12] Liu D, Yu H T, Duan Y Y, et al. New insight into the angle insensitivity of ultrathin planar optical absorbers for broadband solar energy harvesting[J]. Scientific Reports, 2016, 6:32515.
[13] Li Y, Chernikov A, Zhang X, et al. Measurement of the optical dielectric function of monolayer transition-metal dichalcogenides:MoS2, MoSe2, WS2, and WSe2[J]. Physical Review B, 2014, 90(20):205422.
[14] Gray A, Balooch M, Allegret S, et al. Optical detection and characterization of graphene by broadband spectrophotometry[J]. Journal of Applied Physics, 2008, 104(5):053109.
[15] Jariwala D, Davoyan A, Tagliabue G, et al. Near-unity absorption in van der Waals semiconductors for ultrathin optoelectronics[J]. Nano Letters, 2016, 16(9):5482-5487.
