By adjusting thickness and luminous place of the luminous DPVBi layer in the same laboratory conditions

organic light-emitting devices have been produced. We designed different device structures and have produced a luminous device in the experiment. Firstly

we designed a group of devices with same structures perfectly

except different DPVBi layer thickness

as a result

their spectrum changed. When DPVBi layer thickness was 5 nm yellow-light was emitted.When DPVBi layer thickness was 10nm white-light was emitted because blue and yellow light were emitted symmetrically. With increase gradually of DPVBi layer thickness

ingredient of bluelight was increasing

and the emission color of the devices transferred little by little into blue. As a result

the emission hue of device changed due to different thickness of DPVBi layer. Secondly

DPVBi layer was laid on the different places in the device

the luminous performance of the device was different. From the experiment we can see that the DPVBi layer in different place had the different luminous essences: the luminous DPVBi layer before rubrene emitted blue light as a light-emitting layer;but the luminous DPVBi layer after rubrene didn't emitted light. According to compare of HOMO and LUMO energy grade used in the materials

the luminous DPVBi layer after rubrene performed an function of hole block only. This would affect the luminous brightness and efficiency of the organic light-emitting devices to a large extent. If by adjusting reasonably thickness and luminous place of the luminous DPVBi layer

the light hue of devices may be adjusted to gain colors expected. On the other hand

white-light devices were expected to produce

which was significant.