Diffuse Reflectance of Powders and Band gap Measurements at Room Temperature

Introduction

Measuring how powders reflect light is trickier than it looks. Properties like band gap (a key indicator of how a material interacts with light and energy), color-changing behavior, and light absorption are often used to judge a material's potential for real-world applications, but powders are notoriously hard to measure consistently. Small differences in how a sample is prepared or packed can shift the results.

Most methods rely on a single measurement setup and simply report the outcome, without checking whether that result actually holds up. This application note uses the PerkinElmer LAMBDA 1050+ UV/Vis/NIR Spectrophotometer to cross-check results on a range of powder samples, comparing data collected with a 100 mm integrating sphere against data collected with a Praying Mantis diffuse reflectance accessory. Comparing the two shows where the data agrees, where it doesn't, and why, giving researchers a more reliable way to trust their measurements than a single method can offer on its own.