High power spectrometer for the characterization of photovoltaic cells in a controlled atmosphere or vacuum

Abstract

The complete description of a high power spectrometer, allowing for large area illumination of up to 10 ${\mathrm{cm}}^2$ in the wavelength range 200–800 nm with average power densities of 2 mW ${\mathrm{cm}}^2,$ is provided. The setup employs a stationary 150 W xenon lamp used in conjunction with a simple stationary single monochromator grating. The photovoltaic sample under test is placed in a stainless-steel vacuum chamber allowing for operating pressures down to ${10}^{\text{−6}}$ mbar equipped with a quartz window and electrical connections. The entire vacuum chamber was placed on a moving arm allowing for positioning in a selected part of the diffracted beam of the monochromator. The typical spectral resolution was 12 ${\mathrm{nm cm}}^{\text{−1}}$ which gave bandwidths of 25 nm with a 2 cm sample width. The electrical characteristics of the photovoltaic device under test was measured using a source meter giving an experimental current sensitivity of 10 pA. We finally demonstrate the application of the instrumental setup for the characterization of a polymer based photovoltaic.