Quantum Efficiency Measurement - QUANTX-300

Location: Lab 2.20 (CEMOP)
Responsible: Manuel Mendes
The quantum efficiency (Q.E.) is directly related with the photo-response (i.e. photo-generated current) produced by a solar cell. It is given by the ratio of the number of charge carriers supplied by the solar cell to the number of photons of a given energy incident on the cell. If all photons of a certain wavelength are absorbed and the resulting minority carriers are collected, then the quantum efficiency at that particular wavelength is unity; while the quantum efficiency for photons with energy below the band gap is zero.

QUANTX-300 is Newport’s fully-integrated system for Internal Quantum Efficiency (IQE) and External Quantum Efficiency (EQE) measurement of photovoltaic devices. The equipment is a turn-key solution which includes all necessary components with integrated light source, monochromator, detectors, electronics, software, and computer. The QUANTX-300 incorporates a patented detector geometry using a beam splitter, allowing for simultaneous measurement of EQE and the reflective losses to quantify IQE. This model also includes a 4-wire sense which broadens the capabilities to include a large range of sample sizes and efficiencies. A variety of accessory modules are available to provide positive sample positioning, temperature control, and electrical probing capabilities, as well as a light bias system (based in laser diodes) to allow the measurement of tandem (double junction) solar cells.
The acquisition and control software for the QUANTX-300 is installed on a laptop com-puter included with the measurement system. The software uses an intuitive, icon-based graphical interface to provide instrument controls, configuration, and data acquisition.

Instrument Specifications:
Spot Size: 1.1 mm x 1.2 mm at focus
Working Distance: 85 mm
Wavelength Range: 320 - 1800 nm
Wavelength Accuracy: +/- 0.5 nm
Spectral Response Repeatability: < 0.5% of measured value
Programmable Voltage Bias: +/- 10V
Signal Acquisition: Chopper with virtual lock-in amplifier
Chopper Frequency: 4.0 Hz - 100.0 Hz

Electrical/Mechanical Specifications:
Input Voltage: 90 - 264 VAC
Power Consumption: 400 W
Power Supply Operating Mode: Constant current or constant power
Weight: 34 kg
Dimensions (m) (W x D x H): 0.85 x 0.37 x 0.49