Robertsbridge, U.K.-based Photonic Science Ltd. has introduced a high-resolution InGaAs short-wavelength infrared (SWIR) camera for solar cell inspection using laser-induced fluorescence. The company says the camera delivers 640 Ã� 512-pixel resolution with extended dynamic range response up to 2.2 Âµm.
The camera detects voids, cracks and dead areas through sliced and bulk silicon and captures faint laser fluorescence-induced emissions from individual photovoltaic cells and bare silicon wafer substrates. Cracks, and dead or weak responding areas are unveiled on sliced wafers, enabling automatic sorting and selection of the best pieces at up to more than 3,000 wafers per hour.
Features include a high-responsivity InGaAs sensor, low-noise electronics and deep cooling, the company notes. The read-while-expose mode enables a 100% shutterless duty cycle and high sensitivity operation in low-light-level conditions.
Input pixel size is 25 Ã� 25 Âµm, responsivity in low-gain mode is 1.2 ÂµV per electron and, in high-gain mode, 31 ÂµV per electron. The camera operates at 25 fps at full resolution at 10 MHz and has a 16-bit extended dynamic range.