Kraus Theodore J, Nepomnyashchii Alexander B, Parkinson B A
Department of Chemistry, School of Energy Resources, University of Wyoming , Laramie, Wyoming 82071, United States.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):9946-9. doi: 10.1021/am5029507. Epub 2014 Jun 19.
Homoepitaxial growth of highly ordered and pure layers of rutile on rutile crystal substrates and anatase on anatase crystal substrates using atomic layer deposition (ALD) is reported. The epilayers grow in a layer-by-layer fashion at low deposition temperatures but are still not well ordered on rutile. Subsequent annealing at higher temperatures produces highly ordered, terraced rutile surfaces that in many cases have fewer electrically active defects than the substrate crystal. The anatase epitaxial layers, grown at 250 °C, have much fewer electrically active defects than the rather impure bulk crystals. Annealing the epilayers at higher temperatures increased band gap photocurrents in both anatase and rutile.
据报道，使用原子层沉积（ALD）在金红石晶体衬底上同质外延生长高度有序且纯净的金红石层，以及在锐钛矿晶体衬底上同质外延生长锐钛矿层。外延层在低沉积温度下以逐层方式生长，但在金红石上仍未完全有序。随后在较高温度下退火会产生高度有序的梯田状金红石表面，在许多情况下，这些表面的电活性缺陷比衬底晶体更少。在250℃生长的锐钛矿外延层的电活性缺陷比相当不纯的块状晶体少得多。在较高温度下对外延层进行退火会增加锐钛矿和金红石中的带隙光电流。
