Pacer supplies a range of photocells and photodiodes from PerkinElmer, Kodenshi, TT Optek and TAOS.

PerkinElmer offer Silicon PN photodiodes for high volume, low cost applications. Si photodiodes are junction devices which act as light-controlled current sources. Output is proportional to incident illumination and is relatively independent of applied voltage. Bulk-effect devices have no junction. The bulk resistivity decreases with increasing illumination. Current output can be varied by adjusting the applied voltage. PerkinElmer refers to its bulk-effect photoconductors as photocells (light dependent resistors) - a solution for applications requiring sensing of the presence or absence of light.