Interfacial Built-In Electric Field-Driven Direct Current Generator Based on Dynamic Silicon Homojunction.

Yanghua Lu,Haonan Zheng,Zhenzhen Hao,Xutao Yu,Yanfei Yan,Guiting Yang,Runjiang Shen,Panpan Zhang,Qiuyue Gao,Yu Wen,Shisheng Lin

doi:10.34133/2020/5714754

Abstract

Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things. The proposal of a dynamic heterojunction-based direct current generator builds up new platforms for developing in situ energy. However, the requirement of different semiconductors in dynamic heterojunction is too complex to wide applications, generating energy loss for crystal structure mismatch. Herein, dynamic homojunction generators are explored, with the same semiconductor and majority carrier type. Systematic experiments reveal that the majority of carrier directional separation originates from the breaking symmetry between carrier distribution, leading to the rebounding effect of carriers by the interfacial electric field. Strikingly, NN Si homojunction with different Fermi levels can also output the electricity with higher current density than PP/PN homojunction, attributing to higher carrier mobility. The current density is as high as 214.0 A/m2, and internal impedance is as low as 3.6 kΩ, matching well with the impedance of electron components. Furthermore, the N-i-N structure is explored, whose output voltage can be further improved to 1.3 V in the case of the N-Si/Al2O3/N-Si structure, attributing to the enhanced interfacial barrier. This approach provides a simple and feasible way of converting low-frequency disordered mechanical motion into electricity.

Highlights

With the increasing energy demand and scientific development of human being society, constant efforts have been devoted to maintaining the huge energy consumption while minimizing the earth resource cost [1,2,3,4]
With the rapid development of wearable devices and intelligent monitoring equipment [24,25,26,27,28], it is urgent need to look for a high current density in situ energy generator with matching internal impedance with electron component, as a potential candidate for a light and miniaturized functional device, which overcomes the limitation of the environment and weighty external circuit [29,30,31,32,33,34]
The requirement of different semiconductors in dynamic heterojunction is too complex to wide applications, generating energy loss for crystal structure mismatch

Summary

Introduction

With the increasing energy demand and scientific development of human being society, constant efforts have been devoted to maintaining the huge energy consumption while minimizing the earth resource cost [1,2,3,4]. Compared with piezoelectric and triboelectric nanogenerators, this dynamic NN homojunction generator with ultrahigh current density can effectively output a direct current without a rectification circuit and storage unit. This dynamic homojunction generator can charge a capacitor without external rectifying circuits quickly, indicating its advantage and potential applications in in situ energy acquisition fields. This approach provides a simple and feasible way of converting low-frequency disordered mechanical motion into electricity, especially the biomechanical energy, wind power, and tidal energy

Results and Discussion

Interfacial barrier

Materials and Methods

Conflicts of Interest