High performance PbSe colloidal quantum dot vertical field effect phototransistors.
Here, vertical field effect phototransistors (VFEPTs) based on lead selenide colloidal quantum dots (PbSe CQDs) for infrared photo detection were investigated, using Au/Ag nanowires as the source transparent electrode. VFEPTs have the advantage of easy fabrication of ultrashort channel length devices, as the channel length is simply determined here by the PbSe CQDs active layer's thickness (260 nm). In ultrashort channels, photo-excited carriers quickly (in nanoseconds) transfer to the drain. As soon as a hole (electron) reaches the drain, a hole (electron) is replenished from the source. Accordingly, multiple holes circulate in the ultrashort channel following a single electron-hole photo generation. As a result, the device exhibits superior photoconductive properties over the lateral structure. PbSe CQD VFEPTs show ambipolar operation under low voltage down to one volt at room temperature. Moreover, high photo responsivity and high specific detectivity of 2 × 10(4) A W(-1) and 7 × 10(12) Jones are also achieved in the devices under 808 nm laser illumination. The transparent electrode-based near infrared VFEPTs prepared through this self-assembly solution process show promise for applications in electronics and photoelectronics.
Institute of Laser & Opto-Electronics, College of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People's Republic of China. Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin 300072, People's Republic of China.
Haiting
H
Zhang
Yating
Y
Zhang
Xiaoxian
X
Song
Yu
Y
Yu
Mingxuan
M
Cao
Yongli
Y
Che
Jianlong
J
Wang
Junbo
J
Yang
Haitao
H
Dai
Guizhong
G
Zhang
Jianquan
J
Yao