Thermionic converters show highly efficient thermoelectric conversion performance. Compared to metals, graphene materials exhibit excellent optical and electrical properties. A novel solar-driven graphene-anode thermionic converter is proposed, in which a photon reflector is attached to the graphene-anode to reduce dissipation. Expressions for the power output density and efficiency of the system are derived by considering the major irreversible dissipation. The performance characteristics of the system are comprehensively evaluated, including the effects of the voltage output, current density, area ratio of the absorber to the cathode, and solar concentration factor. The results show that the solar-driven graphene-anode thermionic converter with a photon reflector achieves better performance than the case without reflectors, and outperforms the solar-driven metal-anode thermionic converter. Under the same conditions of 3000 solar concentrations, the maximum power output density and efficiency of the proposed system attain 777.2 Wcm⁻² and 44.56%, which increase 24.33% and 115.2%, respectively, compared to those of the solar-driven metal-anode thermionic converter. Besides, the maximum efficiency and power output density of the system at different concentrations and corresponding optimal values of key parameters are calculated. The optimum operating region of the proposed system is determined and the optimum selection criteria of key parameters are provided.

热离子转换器显示出高效的热电转换性能。与金属相比，石墨烯材料表现出优异的光学和电学性能。提出了一种新型太阳能驱动的石墨烯-阳极热离子转换器，其中将光子反射器连接到石墨烯-阳极以减少耗散。系统功率输出密度和效率的表达式是通过考虑主要的不可逆耗散得出的。对系统的性能特性进行了综合评估，包括电压输出、电流密度、吸收体与阴极的面积比以及太阳能集中系数的影响。结果表明，带有光子反射器的太阳能驱动石墨烯-阳极热离子转换器比没有反射器的情况具有更好的性能，并优于太阳能驱动的金属阳极热离子转换器。在3000个太阳能集中的相同条件下，所提出的系统的最大功率输出密度和效率达到777.2 Wcm^-2和 44.56%，与太阳能驱动的金属阳极热离子转换器相比，分别增加了 24.33% 和 115.2%。此外，计算了系统在不同浓度下的最大效率和功率输出密度，以及相应的关键参数最优值。确定了所提出系统的最佳工作区域，并提供了关键参数的最佳选择标准。