Hybrid thermionic-photovoltaic converter with graphene-on-semiconductor heterojunction anode for efficient electricity generation

Hao Qiu; Shisheng Lin; Haoran Xu; Guanghui Hao; Gang Xiao

doi:10.1016/j.isci.2022.105051

Hybrid thermionic-photovoltaic converter with graphene-on-semiconductor heterojunction anode for efficient electricity generation

iScience. 2022 Sep 2;25(10):105051. doi: 10.1016/j.isci.2022.105051. eCollection 2022 Oct 21.

Authors

Hao Qiu¹, Shisheng Lin², Haoran Xu¹, Guanghui Hao³, Gang Xiao¹

Affiliations

¹ State Key Laboratory of Clean Energy Utilization, Zhejiang University, 38 Zheda Road, Hangzhou 310027, China.
² Department of Information Science & Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
³ Cathode Engineering Center, Beijing Vacuum Electronics Research Institute, 13 Jiuxianqiao Road, Beijing 100015, China.

Abstract

Thermionic energy converters are solid-state heat engines to produce electricity with significant potential, whereas the output voltage is constrained by the work function difference between cathode and anode. In this work, we originally apply a graphene-on-semiconductor heterojunction anode to a thermionic-photovoltaic (TIPV) converter to output additional voltage. Thermionic electrons are injected into the graphene layer and then recombined with photogenerated holes. Photogenerated electrons are extracted from the conduction band and reinjected into the cathode through an external load. A proof-of-concept demonstration of the TIPV converter is developed with barium surface-engineered cathode and anode. Open-circuit voltage is increased from ∼0.9 to ∼1.9 V by comparing with an identical configuration without graphene layer. The TIPV converter yields a power generation density of 2.7 kW/m² with an electronic efficiency of ∼27%. This work paves the way for the development of TIPV converter toward high power density.

Keywords: Engineering; Nanomaterials; Photonics.