Quantum Spin Dynamics


Electrically detected magnetic resonance

Recombination centres in Czochralski silicon containing oxide precipitates


Electrically detected magnetic resonance (EDMR) is a very sensitive technique, which can be used for the spectroscopic characterisation of photovoltaic materials on the nanoscale. We have studied the most important recombination centres in Czochralski silicon (Cz-Si) containing strained oxide precipitates (OPs) with a wide range of densities. Cz-Si is used for the vast majority of silicon integrated circuits and ~40% of solar cells, and is known to suffer from various impurities. Strained OPs reveal a square platelet-like shape and are used to confine detrimental impurities to inactive regions of the wafer in a process called internal gettering. The recombination centres associated with intentionally grown OPs as well as with iron-related impurities, such as interstitial iron and the iron-boron pair, are identified via EDMR and discussed. Our results demonstrate that OPs are associated with Pb0 and Pb1 dangling bonds forming at the corners of those platelets.

Spin-dependent recombination in Czochralski silicon containing oxide precipitates

V. Lang, J. D. Murphy, R. J. Falster, and J. J. L. Morton
J Appl Phys 111 013710 (2012) Link

Electrically Detected Magnetic Resonance at High Magnetic Fields 


We have investigated the EDMR effect in silicon field-effect transistors (FETs) and demonstrate the readout of arsenic and phosphorus donor spins in a resonant microwave cavity at 3.36 T and 94 GHz (W-band) for the first time worldwide. A comparison between conventional low- and high-field EDMR on the same devices shows that bolometric heating as well as spin-dependent scattering can be ruled out as the underlying mechanism giving rise to the spin resonance signals in FETs. Our signals are rather understood in terms of a polarisation transfer from the donor to the two-dimensional electron gas forming in the device channel.

Electrically detected magnetic resonance of neutral donors interacting with a two-dimensional electron gas

CC Lo, V Lang, RE George, JJL Morton, AM Tyryshkin, SA Lyon, J Bokor, T Schenkel
Phys Rev Lett 106 207601 (2011) Link

Electrically detected magnetic resonance in a W-band microwave cavity

V Lang, CC Lo, RE George, SA Lyon, J Bokor, T Schenkel, A Ardavan and JJL Morton
Rev Sci Instrum 82 034704 (2011) Link