Low cost 3D-printing used in an undergraduate project: an integrating sphere for measurement of photoluminescence quantum yield

We report upon the exploitation of the latest 3D printing technologies to
provide low-cost instrumentation solutions, for use in an undergraduate level
final-year project. The project addresses prescient research issues in optoelectronics, which would otherwise be inaccessible to such undergraduate
student projects. The experimental use of an integrating sphere in conjunction
with a desktop spectrometer presents opportunities to use easily handled, low
cost materials as a means to illustrate many areas of physics such as
spectroscopy, lasers, optics, simple circuits, black body radiation and data
gathering. Presented here is a 3rd year undergraduate physics project which
developed a low cost (£25) method to manufacture an experimentally accurate
integrating sphere by 3D printing. Details are given of both a homemade
internal reflectance coating formulated from readily available materials, and a
robust instrument calibration method using a tungsten bulb. The instrument is
demonstrated to give accurate and reproducible experimental measurements of
luminescence quantum yield of various semiconducting fluorophores, in
excellent agreement with literature values.