posted on 2024-01-09, 17:05authored byKunrong Du, Ziyuan Meng, Yilian Xi, Nana Liu, Jingwei Zhang, Shengjie Xu, Zhijian Shi, Hongrun Zhang, Shan Wang, Haifeng Feng, Weichang Hao, Hui Pan, Shujun Zhang, Yi Du
Precise
control of charge carrier type and density of two-dimensional
(2D) ambipolar semiconductors is the prerequisite for their applications
in next-generation integrated circuits and electronic devices. Here,
by fabricating a heterointerface between a 2D ambipolar semiconductor
(hydrogenated germanene, GeH) and a ferroelectric substrate (PbMg1/3Nb2/3O3–PbTiO3,
PMN–PT), fine-tuning of charge carrier type and density of
GeH is achieved. Due to ambipolar properties, proper band gap, and
high carrier mobility of GeH, by applying the opposite local bias
(±8 V), a lateral polarization in GeH is constructed with a change
of work function by 0.6 eV. Besides, the built-in polarization in
GeH nanoflake could promote the separation of photoexcited electron–hole
pairs, which lead to 4 times enhancement of the photoconductivity
after poling by 200 V. In addition, a gradient regulation of the work
function of GeH from 4.94 to 5.21 eV by adjusting the local substrate
polarization is demonstrated, which could be used for data storage
at the micrometer size by forming p–n homojunctions. This work
of constructing such heterointerfaces provides a pathway for applying
2D ambipolar semiconductors in nonvolatile memory devices, photoelectronic
devices, and next-generation integrated circuit.