LASER-ABLATION DEPOSITION AS A PREPARATION METHOD FOR SENSOR MATERIALS

In the development of new materials for sensors, laser ablation deposi tion (LAD) offers a relatively easy technique to realise complicated m aterial compositions and multilayer structures. In this paper, LAD of three different thin films for sensor and actuator materials was carri ed out using a Q-switched Nd:YAG laser and an XeCl excimer laser. CuIn Se2 (CIS) and Cu(In, Ga)Se2 (CIGS) are well-established as exceptional ly efficient semiconductors with potential applications in the fields of solar cells, infrared radiation monitors and fibre optic infrared d etectors. CIS and CIGS thin films were deposited by an in situ process on fused silica and single crystal silicon substrates. The compositio n of the target material was largely maintained in the thin films. Lea d zirconium titanate (PZT) materials are widely used in sensor and act uator applications. Laser ablation has been used to produce piezoelect ric thin films for use in a low voltage cantilever bimorph actuator st ructure. Nd-doped PZT films were deposited on to Ag-coated oxidised si licon substrates. Displacements in the order of microns were obtained from a 15 mm long element. Diamond-like carbon thin films also have po tential in sensor applications. By varying the peak power density of t he laser beam and the deposition temperature, it was found to be possi ble to tailor the electrical and optical properties of the deposited f ilms between the extremes of diamond-like and graphite-like carbon.