GEKA offers a number of versions of the DSPC© Analysis software, which target different device applications such as PV , IC, and HB-LED as well as various wafer structures based on different materials including Si and GaN.

The two basic versions of the Analyzer, DA-LS and DA-HS, are suitable for analysis of data from any PCD system, contact or non-contact (RF-PCD and microwave-PCD), that is capable of measuring photoconductance decay.

Typical Results of the LS and HS Modes

           Surf. rec. time constant  0.77 ms
     Carrier rec. lifetime  16.1 μs    Surf. capture velocity  4.29 105 cm/s
     Generation rate (bulk)
 7.95 1014 1/cm2s    Surf. state density  4.44 1011 1/cm2
     Carrier injection level  3.84 1013 1/cm3    Surf. charge  1.41 1011 q/cm2
     Doping concentration  3 1015 1/cm3
 Width of the surf. region.
 449 nm  
    G bulk = 3.5% G
 surf. at 660nm
 Generation rate in surf. region
 2.26 1016 1/cm2s

The third version of the Analyzer, unlike standard Steady-State methods, is capable of measuring Absolute Steady-State Carrier Recombination Lifetime (ASRL)© without requiring measurement of the carrier generation rate. This allows determination of the carrier lifetime in product (device) wafers with textured surfaces. However, this DSPC© modality typically requires direct integration with the photoconductance measuring tool to allow closed loop control of the hardware. The ASRL© modality is particularly useful for characterization of product (device) wafer structures including monitoring of the PV solar cell manufacturing process.

Manufacturing Process Monitoring
EFG Si PV Solar Cell


Back Metal + Bake

     Base Characteristics

Process   τ (μs)  Δn (1/cm3)
 Pre-Metal 7
2.2 1015
 Back Metal + Bake   36 5.3 1015