Characterization of the CuGaSe2/ZnSe Interface Using Kelvin Probe Force Microscopy

2001 ◽  
Vol 668 ◽  
Author(s):  
S. Sadewasser ◽  
Th. Glatzel ◽  
M. Rusu ◽  
A. Meeder ◽  
D. Fuertes Marrón ◽  
...  

ABSTRACTTo improve the efficiency of heterostructure solar cells based on chalcopyrite semiconductors a good understanding of the interface properties is crucial. By Kelvin Probe Force Microscopy it is possible to obtain laterally resolved images of the work function of semiconductor surfaces in addition to the topographical information usually obtained by noncontact atomic force microscopy. We studied the CuGaSe2/ZnSe interface prepared by growth of CuGaSe2 onto the (110) face of freshly cleaved ZnSe single crystals using chemical vapor deposition. We observed different work function values for different crystal facets on single CuGaSe2 grains. From the obtained work function data and surface photovoltage measurements a schematic band diagram for the CuGaSe2/ZnSe heterostructure is proposed.

1999 ◽  
Vol 568 ◽  
Author(s):  
Hernan Rueda ◽  
James Slinkman ◽  
Dureseti Chidambarrao ◽  
Leon Moszkowicz ◽  
Phil Kaszuba ◽  
...  

ABSTRACTmethod for characterizing the mechanical stress induced in silicon technology is described. Analysis by scanning Kelvin probe force microscopy (SKPM) coupled with finite-element (FE) mechanical strain simulations is performed. The SKPM technique detects variations in the semiconductor work function due to strain influences on the band gap. This technique is then used to analyze the strain induced by shallow trench isolation processes for electrical isolation. The SKPM measurements agree with the FE simulations qualitatively.


2020 ◽  
pp. 106060
Author(s):  
Mads Nibe Larsen ◽  
Mads Svanborg Peters ◽  
Rodrigo Lemos-Silva ◽  
Demetrio A. Da Silva Filho ◽  
Bjarke Jørgensen ◽  
...  

2021 ◽  
Author(s):  
Somayeh Asgary ◽  
Amir Hoshang Ramezani ◽  
Zhaleh Ebrahimi Nejad

Abstract WS2 flakes have been grown successfully on SiO2 substrate via chemical vapor (CVD) deposition method by reduction and sulfurization of WO3 using Ar/ H2 gas and sulfur evaporated from solid sulfur powder. The prepared samples were characterized by optical microscopy (OM), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectra and photoluminescence (PL). Large domain WS2 monolayers are obtained by extending the growth time. The perfect triangular single-crystalline WS2 flakes with an average length of more than 35 µm were achieved. The sharp PL peak (∼1.98 eV) and two distinct Raman peaks (E2g and A1g) with a ∼ 71.5 cm-1 peak split indicating that relatively high quality WS2 crystals with a regular triangle shape can be synthesized. Higher growth time shows larger triangular-shaped of WS2.


2020 ◽  
Vol 11 ◽  
pp. 911-921
Author(s):  
Christian Ritz ◽  
Tino Wagner ◽  
Andreas Stemmer

Kelvin probe force microscopy is a scanning probe technique used to quantify the local electrostatic potential of a surface. In common implementations, the bias voltage between the tip and the sample is modulated. The resulting electrostatic force or force gradient is detected via lock-in techniques and canceled by adjusting the dc component of the tip–sample bias. This allows for an electrostatic characterization and simultaneously minimizes the electrostatic influence onto the topography measurement. However, a static contribution due to the bias modulation itself remains uncompensated, which can induce topographic height errors. Here, we demonstrate an alternative approach to find the surface potential without lock-in detection. Our method operates directly on the frequency-shift signal measured in frequency-modulated atomic force microscopy and continuously estimates the electrostatic influence due to the applied voltage modulation. This results in a continuous measurement of the local surface potential, the capacitance gradient, and the frequency shift induced by surface topography. In contrast to conventional techniques, the detection of the topography-induced frequency shift enables the compensation of all electrostatic influences, including the component arising from the bias modulation. This constitutes an important improvement over conventional techniques and paves the way for more reliable and accurate measurements of electrostatics and topography.


ACS Nano ◽  
2018 ◽  
Vol 12 (6) ◽  
pp. 5274-5283 ◽  
Author(s):  
Fabian Schulz ◽  
Juha Ritala ◽  
Ondrej Krejčí ◽  
Ari Paavo Seitsonen ◽  
Adam S. Foster ◽  
...  

Nanoscale ◽  
2020 ◽  
Vol 12 (15) ◽  
pp. 8216-8229
Author(s):  
Hong-Ki Kim ◽  
Soo In Kim ◽  
Seongjun Kim ◽  
Nam-Suk Lee ◽  
Hoon-Kyu Shin ◽  
...  

In the defective SiC epitaxial layer, the work function variation was observed by Kelvin probe force microscopy (KPFM), and the work function difference came from the variation of polytype and the disordered surface.


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