Wednesday, November 14, 2012
[Ru(bpy)3](BF4)2 for OLEDs
A coordination complex between a transparent tin oxide electrode and an active metal electrode produces light when an external voltage is supplied. Frabrication of OLEDs is a art, beacause you need perfectly spin-coater control and the right materials. In this post I compiled from diferent web sites and articles how to get OLEDs with [Ru(bpy)3](BF4)2 in thin layers between two conductin glass electrodes. Too thin a coating of the [Ru(bpy)3](BF4)2 polyvinylalcohol layer will give a short circuit and no light; too thick a coating will have a large electrical resistance and no light. to prepare [Ru(bpy)3](BF4)2: 1. Measure 0.083 g (to the nearest 0.001 g) of the dried RuCl3 (MM = 207.45 g) in a 30mL beaker and place a stirbar in it. 2. Add 8 mL of water to the beaker, clamp it to a ring stand, and place beaker on top of a heater/magnetic stirrer. Turn the heat on ~ 5 and start mixing the solution. 3. In a weigh boat, measure 0.188 g (to the nearest 0.001 g) of 2,2’dipyridyl (MM = 156.19 g) and add to the beaker. 4. Use a micropipette to measure out 440 mL of NaH2PO2 into the beaker. Cover with a watch glass to prevent evaporation, and mark the initial water level on the outside of the beaker with a permanent marker. 5. Reflux the solution for 30 minutes. If the solution starts to bubble too rapidly, turn down the variac. During this time, check the water level every 5 minutes or so, and add additional water to maintain volume if necessary. After [Ru(bpy)3](BF4)2 synthesis get a cunductive glass pieace and identify the conducting side of a tin oxide-coated piece of glass by using a multimeter to measure resistance. The conducting side will have a finite resistance of 20-30 ohms.