scholarly journals Novel approach to passivation of InAs/GaSb type II superlattice photodetectors

2019 ◽  
Vol 125 (12) ◽  
Author(s):  
E. Papis-Polakowska ◽  
J. Kaniewski ◽  
A. Jasik ◽  
K. Czuba ◽  
I. Sankowska ◽  
...  
Keyword(s):  
Dark Current ◽  
Self Assembled Monolayers ◽  
Type Ii ◽  
Force Microscopy ◽  
Type Ii Superlattice ◽  
Atomic Force ◽  
Novel Approach ◽  
Assembled Monolayers ◽  
Order Of Magnitude ◽  
Contact Angle Analysis

Abstract The innovative two-step passivation by octadecanethiol (ODT) self-assembled monolayers (SAMs) and the following silicon dioxide (SiO2) deposition was used for the type-II InAs/GaSb superlattice photodetector. To understand the mechanism of passivation, the (100) GaSb surface covered with the ODT and, for comparison, with the biphenyl thiol (BPT), was characterized by the atomic force microscopy, Raman spectroscopy and contact angle analysis. The results of the study indicated the presence of the homogeneous both the ODT and the BPT monolayers; however, the ODT SAMs were more stable. Therefore, the ODT-based wet treatment was used in the two-step passivation resulting in a reduction of the dark current by one order of magnitude for passivated detector compared with an unpassivated device.

Self-assembled monolayers of sulfonate-terminated alkanethiols investigated by frequency modulation atomic force microscopy in liquid

2017 ◽  
Vol 28 (45) ◽  
pp. 455603 ◽  
Author(s):  
Hitoshi Asakawa ◽  
Natsumi Inada ◽  
Kaito Hirata ◽  
Sayaka Matsui ◽  
Takumi Igarashi ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Frequency Modulation ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Mobility of charge carriers in self-assembled monolayers

2019 ◽  
Vol 10 ◽  
pp. 2449-2458
Author(s):  
Zhihua Fu ◽  
Tatjana Ladnorg ◽  
Hartmut Gliemann ◽  
Alexander Welle ◽  
Asif Bashir ◽  
...  
Keyword(s):  
Charge Transport ◽  
Charge Carrier Mobility ◽  
Charge Carriers ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mobility Of Charge Carriers ◽  
Assembled Monolayers ◽  
Self Assembled

We present a new approach to study charge transport within 2D layers of organic semi-conductors (OSCs) using atomic force microscopy (AFM)-based lithography applied to self-assembled monolayers (SAMs), fabricated from appropriate organothiols. The extent of lateral charge transport was investigated by insulating pre-defined patches within OSC-based SAMs with regions of insulating SAM made from large band gap alkanethiolates. The new method is demonstrated using a phenyl-linked anthracenethiolate (PAT), 4-(anthracene-2-ylethynyl)benzyl thiolate. I–V characteristics of differently shaped PAT-islands were measured using the AFM tip as a top electrode. We were able to determine a relationship between island size and electrical conductivity, and from this dependence, we could obtain information on the lateral charge transport and charge carrier mobility within the thin OSC layers. Our study demonstrates that AFM nanografting of appropriately functionalized OSC molecules provides a suitable method to determine intrinsic mobilities of charge carriers in OSC thin films. In particular, this method is rather insensitive with regard to influence of grain boundaries and other defects, which hamper the application of conventional methods for the determination of mobilities in macroscopic samples.

Mechanical Properties of Oligothiophene Self Assembled Films by Atomic Force Microscopy.

2005 ◽  
Vol 871 ◽  
Author(s):  
Imma Ratera ◽  
Jinyu Chen ◽  
Amanda Murphy ◽  
Frank Ogletree ◽  
Jean M. J. Fréchet ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Cell Dimensions ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Unit Cell Dimensions

AbstractThe oligothiophene derivative (4-(5″″-tetradecyl-[2,2′;5′,2″;5″,2″′;5″′,2″″] pentathiophen-5-yl)-butyric acid (C14-5TBA) was synthesized and the structural and mechanical properties of self-assembled monolayers on mica have been studied by atomic force microscopy (AFM). The films were prepared by drop casting a dilute THF solution (1mM) of the oligothiphene on mica. Islands containing primarily monolayers with a very small percentage of multilayers were formed. The molecules adsorb through the carboxylic group, and expose the alkyl chain (CH2)13CH3. High resolution AFM scans reveal a well ordered structure of molecules with unit cell dimensions of 0.65 and 0.46 nm. Applying load to the tip, the molecular film was gradually compressed from an initial height of 4.1nm to a final one of 2.6 nm, corresponding to atilt of the alkyl chains. In regions covered with bilayers the molecules in the second layer were oriented opposite to those in the first layer, thus exposing the carboxylic end group to the air. These second layer was easily removed as the tip pressure increased.

Lattice Structure of Self-Assembled Monolayers of Dialkyl Sulfides and Calix[4]arene Sulfide Adsorbates on Au(111) Revealed by Atomic Force Microscopy

Langmuir ◽  
1999 ◽  
Vol 15 (17) ◽  
pp. 5541-5546 ◽  
Author(s):  
Holger Schönherr ◽  
G. Julius Vancso ◽  
Bart-Hendrik Huisman ◽  
Frank C. J. M. van Veggel ◽  
David N. Reinhoudt
Keyword(s):  
Atomic Force Microscopy ◽  
Lattice Structure ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Dialkyl Sulfides
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