Sinton WCT and Suns-Voc lifetime measurements

Location: Lab 2.1.18 in CEMOP (Uninova 2)
Responsible: Hugo Águas (ext: 10615) and Tiago Mateus

 

Description:
The Sinton WCT-120 is used to measure carrier recombination lifetimes of c-Si wafers (typically after processing and/or depositing additional layers) using either quasi steady-state photoconductance or transient photoconductance decay technique. Calibrated lifetime measurements can yield the implied open circuit voltage (the upper limit for Voc which is a representation of the passivation quality) along each process step.
The Suns-Voc is used to measure the illumination-Voc curve to provide further infor-mation on the material and passivation quality. The open circuit measurement is not affected by series resistance, and therefore can be used for shunt characterization. Also, comparing the Suns-Voc curve with the final I-V curve of the device can give an indication of series resistance.

WCT-120 Specifications:
The system consists of the instrument stage integrated with an eddy-current conduct-ance sensor, a reference cell, a filtered Xenon flash lamp, a flash power supply, and a Windows computer (shared with Suns-Voc) and data acquisition system.

Lifetime measurement range: 100 ns - 10 ms
Measurement (analysis) modes: QSSPC, transient, and generalized lifetime analysis
Resistivity measurement range: 3 – 600 (undoped) Ohms/sq
Available light bias range: 0 - 50 suns
Calibrated injection range: 1013–1016 cm-3
Available spectrum: White-light and IR illumination
Dimensions: 22.5 cm W x 28 cm D x 57 cm H
Ambient operating temperature: 20°C – 25°C

Samples requirements:
-    Material: c-Si wafer before metallization
-    Sample size: 40 – 210 mm diameter
-    Wafer thickness range: 10 – 2000 μm (calibrated)

Suns-Voc Specifications:
The system consists of the instrument stage with integrated chuck and reference cell, a Xenon flash lamp, a flash power supply, a Windows computer (shared with WCT) and a data acquisition system.

Typical calibrated illumination range: 0.006–6 suns
Dimensions: 32 cm W x 28.5 cm D x 75 cm H
Ambient operating temperature: 18°C – 25°C

Samples requirements:
-    Must have a p-n junction that is contactable on both sides of the junction
-    Sample size: maximum 240-mm diameter/side