PearL and t-PearL
Comprehensive photoluminescence characterization of compound semiconductor thin-films.
Spectroscopic photoluminescence (sPL) gives access to information on the band gap, electronic defects and the related composition of materials, e.g. the gallium/(gallium+indium) ratio andcontent of CIGS solar cells. LayTec’s sPL has a total measurement and analysis time of only 100 ms.
PearL can also be combined with LayTec’s time-resolved photoluminescence metrology system t-PearL (trPL) for comprehensive electronic characterization of thin film semiconductors by means of direct charge carrier lifetime measurements. It analyzes the time-dependent decay of photoluminescent radiation emitted from a probed surface after excitation with laser light. Thereby it provides a direct metric for the carrier lifetime. It is designed for in-line integration in production lines or in a vacuum environment. In particular, the option of vacuum integration can be very advantageous for characterizing uncompromised surfaces. Generally, PearL and t-PearL can also be used as components in LayTec’s combined and fully integrated ILMetro in-line.
Monitoring of band gap and charge carrier lifetimes during deposition or ageing
Composition monitoring (if related to bandgap)
Fast detection of the effective Ga content of the absorber in CIGS-based production lines
Product version for CdTe absorbers also available
Spectral and time-resolved PL monitoring for a wide range of excitation wavelengths
Detection in VIS or NIR spectral ranges
Lifetime resolution down to 5 ns
Can be combined with spectral reflectance monitoring (InspiRe) in shared measurement head
Spectral analysis by multi-peak fitting algorithms
tr-PL transients can be fitted by mono- or biexponential decay functions
Adaptable to every in-line process via customized optical heads and mounts
In-line integration for 100% inspection of produced modules
Spatially resolved spectral photoluminescence measurements through multiple heads
Fast data acquisition for in-line measurements on moving substrates
Up to 10 measurements per secondAutomated spectrum analysis calculation of key parameters e.g. Ga/(Ga+In) and Cu content of CIGS layers
PV-line software integration via Profibus, Ethernet, TCP/IP or other protocols for automated operation
Features
Full deconvolution of PL peak to identify contributing species which might have been caused by incomplete reactions of the reactants during film formation
Egap measurements of multiple contributions
Monitoring of PL intensity as a primary indicator for semiconductor quality during ramp up of coating campaigns
Determination of charge carrier lifetime for mono- and bi-exponential decay modes
Whilst being a rather abstract parameter for conventional process optimization, time-resolved PL is gaining growing attention for AI-driven high-throughput approaches as it very well correlates to the final device quality
Combination with InspiRe for reflectance monitoring in shared measurement head
Similar to Flames, PearL and t-PearL can be components of ILMetro stations
In-situ versions for low temperature processes are available
Contact
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