Lead Sulfide Quantum Dot Photodetector with Enhanced Responsivity through a Two-Step Ligand-Exchange Method

Tang，Haodong1; Zhong，Jialin1; Chen，Wei3; Shi，Kanming1,4; Mei，Guanding1; Zhang，Yuniu1; Wen，Zuoliang1; Müller-Buschbaum，Peter3; Wu，Dan2; Wang，Kai1; Sun，Xiao Wei1,4

2019-10-25

10.1021/acsanm.9b00889

ACS Applied Nano Materials   影响因子和分区

25740970

2574-0970

Recently, lead sulfide (PbS) quantum dots (QDs) have demonstrated great potential in becoming one of the most promising next-generation photoelectrical materials for photodetectors. PbS QDs provide fascinating properties including size-controllable spectral sensitivity, a wide and tunable absorption range, cost-efficient solution processability, and flexible substrate compatibility. One of the key problems that limit the performance of PbS QDs-based photodetectors is inefficient carrier transfer. Long ligands decorating the outside surface of PbS QDs to protect them against degeneration inhibit the transfer of electrical charge carriers and thereby limit the device performance. To overcome this problem, the long ligands need to be effectively exchanged. Here, a two-step ligand-exchange method is demonstrated. The QDs are pretreated using methylammonium iodide in solution as the first step ligand exchange before the layer-by-layer deposition process and solid-state ligand exchange. The grazing-incidence small-angle X-ray scattering and X-ray photoelectron spectroscopy analyses prove a smaller spacing among the QDs and an increased ligand-exchange ratio by adopting the two-step method. This strongly indicates a better capability of charge transfer than the traditional one-step solid-state ligand-exchange technology. Devices fabricated using the two-step method present an enhancement of the charge-transfer capability with a larger current. The efficient charge transfer is further demonstrated by a significant 94% increase of the responsivity and a 57% enhancement of the detectivity of the PbS QDs-based photodetector, reaching 3302 mA/W and 5.06 × 10 J, respectively.

GISAXS ligand exchange photodetectors quantum dots solution process

EI ; SCI

英语

通讯

Tianjin New Materials Science and Technology Key Project[16ZXCLGX00040]

Science & Technology - Other Topics ; Materials Science

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000507667200009

American Chemical Society

20193907474625

Charge transfer ; Deposition ; IV-VI semiconductors ; Lead compounds ; Ligands ; Nanocrystals ; Photodetectors ; Photons ; Spectroscopy ; Sulfur compounds ; X ray photoelectron spectroscopy ; X ray scattering

Semiconductor Devices and Integrated Circuits:714.2 ; Nanotechnology:761 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Chemical Operations:802.3 ; Atomic and Molecular Physics:931.3 ; High Energy Physics:932.1

2-s2.0-85074676293

Scopus

1.Guangdong University Key Lab for Advanced Quantum Dot Display and Lighting,Shenzhen Key Lab for Advanced Quantum Dot Display and Lighting,Department of Electrical and Electronic Engineering,Shenzhen,518055,China
2.Academy for Advanced Interdisciplinary Studies,Department of Electrical and Electronics Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Physik-Department,Lehrstuhl für Funktionelle Materialien,Technische Universität München,Garching,James-Franck-Straße 1,85748,Germany
4.Shenzhen Planck Innovation Technologies Company Ltd.,Shenzhen,China

Tang，Haodong,Zhong，Jialin,Chen，Wei,et al. Lead Sulfide Quantum Dot Photodetector with Enhanced Responsivity through a Two-Step Ligand-Exchange Method[J]. ACS Applied Nano Materials,2019,2(10):6135-6143.

Tang，Haodong.,Zhong，Jialin.,Chen，Wei.,Shi，Kanming.,Mei，Guanding.,...&Sun，Xiao Wei.(2019).Lead Sulfide Quantum Dot Photodetector with Enhanced Responsivity through a Two-Step Ligand-Exchange Method.ACS Applied Nano Materials,2(10),6135-6143.

Tang，Haodong,et al."Lead Sulfide Quantum Dot Photodetector with Enhanced Responsivity through a Two-Step Ligand-Exchange Method".ACS Applied Nano Materials 2.10(2019):6135-6143.