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Electrical semiconductor characterization
Luminescence dating, research, dosimetry and more
Contamination monitor, beta-aerosol monitor, dose rate meter and more
for ultra-fast crystal orientation, crystal alignment in production, quality control, rocking curve measurements, material...
state-of-the-art XRD system for automatic single crystal ingot orientation, tilting and alignment for grinding
Wafer sorting, crystal orientation, resistivity, optical notch and flat determination
Flexible diffractometer for ultra-fast Omega Scan orientation determination
Smart diffractometer for ultra-fast Omega-scan of small samples.
Robust XRD equipment for fully automated in-line testing & alignment
for blanks, wafers & bars (AT, SC, TF, etc.)
three generations of X-ray engineers
in industrial production, R&D and more
discover the most convenient way of measuring orientation of single crystals
Mono- and Multi-crystalline wafer lifetime measurement device
Low cost table top lifetime measurement system for characterization of a variety of different silicon samples at different...
Mono- and Multi-crystalline wafer and brick lifetime measurement device
for production and quality control of monocrystalline Si ingots,bricks and wafers
Flexible OEM unit for lifetime measurements at a variety of different samples ranging from mono- to multicrystalline silicon...
for contactless and temperature dependent lifetime and LBIC measurements
High Resolution Resistivity Mapping Tool for process control and quality assurance measurements
The minority carrier life time is sensitive for all kinds of electrically active defects in semiconductors and is therefore...
MDP is an advanced technology with a so far unsurpassed combination of sensitivity, speed and resolution for fab and lab...
High sensitivity, high resolution surface photovoltage (SPV) measurement instrument
High sensitivity, high resolution surface photovoltage spectroscopy (SPS) instrument with a variable energy excitation source...
for quality control of bifacial PERC/PERC+ solar cells and more
portable in field PID tester for solar modules
user friendly and advanced operating software
The PIDcon devices are designed to investigate the PID susceptibility for production monitoring of solar cells as well as tests...
Learn more about the reasons for PID and the how the susceptibility of solar cells, mini modules and encapsulation materials can...
Our quality management system is an integrated process-oriented system with ISO 9001 certification.
Aim
Photocatalytic materials such as TiO2 are of great interest, for example, for cleaning of industrial wastewater and for water splitting. The identification of directed charge transfer is important for deeper understanding of the role of defect states, defect bands and doping as well as for technology control.
Solution
SPV spectroscopy in the dc (Kelvin probe, measurement of the contact potential difference, DCPD) and ac (modulated) modes provides information about preferential directed charge separation [1] and allows the investigation of the influence doping on band bending, recombination losses and scavengers (entities accepting electrons or holes) at surfaces.
Application example
It was shown that TiO2 can be doped n- and p-type by thermal treatment in reducing or oxidizing atmosphere (figure 1, more in [2]). Figure 2 shows the deposition temperature dependence of defect and band gap transitions in TiO2 after deposition by cold gas spraying of TiO2 powder (more in [3]). The evolution of defect bands in TiO2 caused by incorporation, of nitrogen and their effect on charge transfer was studied in [4].
[1] Th. Dittrich, S. Fengler, “Surface photovoltage analysis of photoactive materials”, World Scientific, 2020.
[2] M. K. Nowotny, et al., „Observation of p-type semiconductivity in titanium dioxide at room temperature”, Materials Letters 64 (2010) 928.
[3] I. Hermann-Geppert, et al., „Cold gas sprayed TiO2-based electrodes for the photo-induced water oxidation”, ECS Transactions 58 (2014) 21.
[4] R. Beranek, et al., „Exploring the electronic structure of nitrogen-modified TiO2 photocatalysts through photocurrent and surface photovoltage studies”, Chem. Phys. 339 (2007) 11.
µPCD/MDP (QSS)
PID
X-ray diffraction
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