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Rare Earth Doping of Porous Silicon

Summary

This can be applied on street lighting, head lights for vehicles, IR camera and semiconductor devices. As well-known, porous silicon is a material that can emit visible light. Since its spectrum is broad, it is not suitable for light emitting device (LED) application. Doping the foreign element(s) can not only significantly improve the brightness, but also can make the spectrum narrow. However, existing doping techniques including co-deposition, ion-implantation, and electro-chemical deposition have problems such as low productivity, long processing time and difficult in mass production etc. The present invention introduces a novel and compatible method for doping the rare earth (RE) phosphors into porous silicon, which can significantly enhance brightness by ten times or give infrared (IR) emission.

Technology Benefits

Possible to freely change the optical property of porous silicon, produce a narrower bandwidth luminescence spectrum and better color tuning over the visible light emission.

Technology Application

Street lighting, head lights for vehicles, IR camera and semiconductor devices.

Detailed Technology Description

It introduces doping rare earth elements into porous silicon that results in enhancement of luminescence. The doping is an electro-chemical process using constant voltage bias across the two electrodes in which the anode is porous silicon and the cathode is platinum. The doping process involves a well-defined solution of electrolytes that controls the conductivity of the solution, and set values of constant voltages that selectively allow the desired rare earth elements being doped into porous silicon.

Supplementary Information

Patent Number: US6056868A
Application Number: US199883124A
Inventor: Cheah, Kok Wei | Wong, Wai Kwok | Gong, Meng Lian | Zheng, Wan Han
Priority Date: 22 May 1998
Priority Number: US6056868A
Application Date: 22 May 1998
Publication Date: 2 May 2000
IPC Current: H01L003334
US Class: 205769 | 204515 | 205766
Title: Rare earth doping of porous silicon
Usefulness: Rare earth doping of porous silicon
Summary: For doping rare earth metals into porous silicon.
Novelty: Doping rare earth metals into porous silicon using constant voltage bias passed between two electrodes in an electrolyte solution

Industry

Electronics

Sub Category

Semiconductor

Application Date

1998.05.22

Application No.

US 09/083,124

Others

Granted

ID No.

H01/CK/Rare/US01

Country/Region

Hong Kong