X-ray Photoelectron Spectrometer

X-ray Photoelectron Spectroscopy (XPS), based on the photoelectric effect, is an analytical technique that directs a monochromatic beam of x-rays onto a sample and detects the characteristic electrons that are ejected. The energies and number of these electrons can be used to determine the elements present on the sample surface and chemical bonding state. Elements from Li to U can be detected. The technique is highly surface sensitive – the typical detection depth is ~5 nm. Usually solids are analyzed, but liquids can be done (very low vapor pressure or freezing is needed). When combined with ion etching, XPS can be used to compile a depth profile – an evaluation of the variation of composition with depth.

Sinton WCT-120 Lifetime Tester

Contactless method for measuring and/or extracting lifetime, dark saturation current, implied Voc, pseudo fill factor, and other parameters with reasonable understanding of solar cell physics, which is ideal for monitoring multicrystalline wafers, dopant diffusions, and low-lifetime samples.

 Auger Electron Spectrometer

Auger electron spectroscopy is a common surface analytical technique. In AES, we use high energy electron to remove a core electron of atom on the surface. Then the electron in outer shell jumps back and release energy. Another core electron absorbs the energy, emits, and generates the signal.

Nano-indenter

Nano indentation is used to obtain elastic modulus and hardness of thin films. Based on the method proposed by Oliver and Pharr, the elastic modulus E and hardness H can be derived directly from the analysis of unloading force vs. displacement curve.

Inverse Photoelectron Spectrometer

 IPES is a surface science technique to probe unoccupied density of states above the fermi level. The relaxation of electrons from high energy states within the sample will emit light in the UV that is detected by a position sensitive detector. The energy of emitted light provides insight into the energy bands in the material.