Modulated optical and ferroelectric properties in a lateral structured ferroelectric/semiconductor van der Waals heterojunction

Abstract

Modulation between optical and ferroelectric properties was realized in a lateral structured ferroelectric CuInP2S6 (CIPS)/semiconductor MoS2 van der Waals (vdW) heterojunction. The ferroelectric hysteresis loop area was modulated by the optical field. Two types of photodetection properties were realized in a device by changing the ON and OFF states of the ferroelectric layer. The device was used as a photodetector in the OFF state but not in the ON state. Higher tunnelling electroresistance (TER) (~1.4×104) in a lateral structured ferroelectric tunnelling junction was crucial, and it was analyzed and modulated by the barrier height and width of the ferroelectric CIPS/semiconductor MoS2 Schottky junction. The new parameter of the ferroelectric hysteresis loop area as a function of light intensity was introduced to analyze the relationship between the ferroelectric and photodetection properties. The proposed device has potential application as optoelectronic sensory cells in the biological nervous system or as a new type of photodetector.

BaTiO3/p-GaN/Au self-driven UV photodetector with bipolar photocurrent controlled by ferroelectric polarization

“…[8][9][10][11][12][13] Most of the reported ferroelectric semiconductor UV photodetectors are based on a simple metal-ferroelectric material-metal structure, in which the photogenerated carriers are separated only/mainly through ferroelectric depolarization field to achieve self-driven operation. [10,[14][15][16][17] Compared with traditional self-driven semiconductor photodetectors based on p-n or Schottky junctions, ferroelectric semiconductor devices can generate bipolar photocurrent by adjusting the direction of the ferroelectric depolarization field, which has a wide application prospect in optical communication, neuromorphic vision devices and logic circuits, [18][19][20][21][22][23][24] but they commonly suffer from the lower responsivity (10 −7 -10 −4 A/W). [25][26][27][28][29] To solve this problem, combining ferroelectric materials with other semiconductors to construct heterojunctions should be an effective approach and has been widely adopted recently.…”