Abstract—An improved Tungsten light source system forphotovoltaic cell testing constructed from low-cost,commercially available materials is presented as an alternativeto current high-cost solar simulators. In this work, spectralcorrection of the Tungsten light source is achieved byincreasing the colour temperature to ~5200 K usinginexpensive commercially available filters. Spectralmeasurements of the corrected light source reveal that a betterspectrum match towards the solar spectrum is achieved thanwhat has been previously demonstrated by our team.Specifically, the improved solar spectrum match is achieved bysubstantial filtering of the infrared range. The proposed setupis used to evaluate the performance of both silicon and organicbased solar cells. Keywords-Photovoltaic, light source, testing, I-Vmeasurement.