Goal By doping TiO 2 with both Cr and N, it is hoped to decrease - PowerPoint PPT Presentation

Goal • By doping TiO 2 with both Cr and N, it is hoped to decrease the band gap of the parent insulating TiO 2 to achieve a photovoltaic device that could operate in the visible region.

Samples • Powder Cr/N TiO 2 : N was not stable • Amorphous 3% Cr, N, and Cr/N TiO 2 300C • Rutile 5% Cr/N TiO 2 : 350C-800C • Anatase 3% N TiO 2 : 350C-800C • Rutile Cr, N, and Cr/N TiO 2 700C • Rutile Cr/N TiO 2 700C diff pressure

Nitrogen

N K XAS

N only TiO 2 300C (noncry)

Cr/N TiO 2 300C (noncry)

N-K XAS

Cr/N 350C Rutile (uncalibrated)

Cr/N 550C Rutile (uncalibrated)

Cr/N 800C Rutile

Difference Spectra

N K Anatase TiO 2

Cr, N, Cr/N TiO 2 700C

Cr/N Rutile 700C

N Rutile 700C

Cr/N 3x10-4T 5-24-10

TiN

Oxidized TiN

Oxygen and Chromium

Cr, Cr/N, and undoped TiO 2 300C

O K and Cr L 2,3 edges

Cr, N, Cr/N TiO 2 700C

Titanium

TiO 2 and Cr/N TiO 2 300C

Undoped TiO 2 300C (not normalized)

Cr/N TiO 2 300C (not normalized)

Ti L 2,3 edge

Ti L 2,3 edge

Ti Emission ALS June 2010

Cr/N TiO 2 800C Rutile

Optical Absorption