A new real-time quantum efficiency measurement system

We have developed a new technique for measuring the quantum efficiency (QE) in solar cells in real-time using a unique, electronically controlled, full-spectrum light source. Full-spectrum QE graphs can be obtained in less than one second (as opposed to 20 minutes using traditional QE instruments). The high measurement speed is achieved by parallel processing of information from a multitude of spectral channels encoded in modulation frequency bands. The reduction in time scale makes this QE measurement technique compatible with inline production diagnostics, high-fidelity, spectral-matching cell binning, and thin-film module spatial spectral response uniformity tests. The instrument is completely solid-state with no moving parts, is robust enough for manufacturing environments, and is significantly less expensive than a traditional QE instrument.