Encapsulation of organic light-emitting diode using thermal chemical-vapour-deposition polymer film

The encapsulation effect of thermal chemical-vapour-deposition polymer films (TCVDPF) has been studied for organic light-emitting diodes (OLED). We used poly- p -xylylene (PPX) and/or poly-2-chloro- p -xylylene (PCPX) films as TCVDPF. For the encapsulation, TCVDPF was deposited on the OLED during a dry process at room temperature. The lifetime of an encapsulated OLED with 0.6 µm thick TCVDPF was about four times longer than that of a non-encapsulated OLED in air. The lifetime of the OLED increased with increasing thickness of the TCVDPF. We conclude that the effect of TCVDPF encapsulation on the long-term stability of the OLED is due to the prevention of oxygen and moisture in air and several other factors.