Si(Li) detectors These consist essentially of a 3–5 mm thick silicon junction type p-i-n diode (same as PIN diode) with a bias of −1000 V across it. The lithium-drifted centre part forms the non-conducting i-layer, where Li compensates the residual acceptors which would otherwise make the layer p-type. When an X-ray photon passes through, it causes a swarm of electron-hole pairs to form, and this causes a voltage pulse. To obtain sufficiently low conductivity, the detector must be maintained at low temperature, and liquid-nitrogen cooling must be used for the best resolution. With some loss of resolution, the much more convenient Peltier cooling can be employed.
si(li) detectors these consist essentially of a 3–5 mm thick silicon junction type p-i-n diode (same as pin diode) with a bias of −1000 v across it the lithium-drifted centre part forms the non-conducting i-layer where li compensates the residual acceptors which would otherwise make the layer p-type when an x-ray photon passes through it causes a swarm of electron-hole pairs to form and this causes a voltage pulse to obtain sufficiently low conductivity the detector must be maintained at low temperature and liquid-nitrogen cooling must be used for the best resolution with some loss of resolution the much more convenient peltier cooling can be employed