Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Grand Energy Program, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Nat Commun. 2016 Oct 20;7:13167. doi: 10.1038/ncomms13167.
The maximal Shockley-Queisser efficiency limit of 41% for single-junction photovoltaics is primarily caused by heat dissipation following energetic-photon absorption. Solar-thermophotovoltaics concepts attempt to harvest this heat loss, but the required high temperatures (T>2,000 K) hinder device realization. Conversely, we have recently demonstrated how thermally enhanced photoluminescence is an efficient optical heat-pump that operates in comparably low temperatures. Here we theoretically and experimentally demonstrate such a thermally enhanced photoluminescence based solar-energy converter. Here heat is harvested by a low bandgap photoluminescent absorber that emits thermally enhanced photoluminescence towards a higher bandgap photovoltaic cell, resulting in a maximum theoretical efficiency of 70% at a temperature of 1,140 K. We experimentally demonstrate the key feature of sub-bandgap photon thermal upconversion with an efficiency of 1.4% at only 600 K. Experiments on white light excitation of a tailored Cr:Nd:Yb glass absorber suggest that conversion efficiencies as high as 48% at 1,500 K are in reach.
单结光伏的最大 Shockley-Queisser 效率极限为 41%，主要是由于能量光子吸收后的热量耗散造成的。太阳能热电光伏概念试图利用这种热损失，但所需的高温（T > 2000 K）阻碍了器件的实现。相反，我们最近证明了热增强光致发光如何成为一种高效的光学热泵，可在相对较低的温度下工作。在这里，我们从理论和实验两方面证明了这种基于热增强光致发光的太阳能转换器。在这里，热量是由一个低带隙光致发光吸收体收集的，该吸收体向一个更高带隙的光伏电池发出热增强光致发光，从而在 1140 K 的温度下产生了 70%的最大理论效率。我们在 600 K 时仅用 1.4%的效率实验证明了亚带隙光子热上转换的关键特性。对定制的 Cr:Nd:Yb 玻璃吸收体的白光激发实验表明，在 1500 K 时的转换效率高达 48%是可以实现的。
