Light traps alternating

The standard molybdenum contact is characterized by low optical reflection, which becomes relevant in efforts to reduce the absorber thickness (light trapping). A study of other metals has not identified clearly promising alternatives [78], Hence, an ohmic contact between TCO and chalcopyrite with good electrical and optical properties could also be useful in developing a cell with a high reflectivity metal/TCO back contact. 

An alternative mechanism by which additives may protect polymers from photo-oxidation is radical trapping. Additives which operate by this mechanism are strictly light stabilizers rather than antioxidants. The most common materials in this class are the hindered amines, which are the usual additives for the protection of poly (ethylene) and poly (propylene). The action of these stabilisers is outlined in Reactions 8.3-8.5. 

FIG. 15.4 Light-driven motion of a gjasa bead trapped in an NPC-02 droplet. The glass bead was captured under alternating UV and blue-light photoirradiation (a, b, and c) and conve> d by the alternating photoirradiation (d and e). 

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