Abstract A molecular adlayer of biphenyl was vapor deposited amorphously onto a single crystal of cryogenically cooled Al2O3. The biphenyl conformer at deposition was determined to be non-planar with a fluorescence λmax ~320 nm. At 161 K biphenyl underwent a disorder-to-order transition which was a planar conformation analogous to the solid crystal with a fluorescence λmax ~345 nm and characterized by a lower fluorescence intensity due to energy transfer. To demonstrate homoepitaxy, a molecular adlayer of biphenyl was vapor deposited and annealed above the disorder-to-order transition temperature. The thinnest adlayer for epitaxial ordering was 35 ML, monolayers, and epitaxy was achieved up to 5000 ML. Heteroepitaxy was demonstrated with p-xylene substrate with biphenyl overlayer. In addition the passage of the xylene through the biphenyl overlayer increased the density of crystalline defect sites and resulted in enhanced fluorescence intensity.

中文翻译：

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芳烃基体上联苯的外延有序化

摘要 在低温冷却的 Al2O3 单晶上非晶气相沉积联苯分子吸附层。沉积时的联苯构象异构体被确定为非平面的，荧光 λmax ~320 nm。在 161 K 时，联苯经历了无序到有序的转变，该转变是类似于固体晶体的平面构象，具有荧光 λmax ~345 nm，并且由于能量转移而具有较低的荧光强度。为了证明同质外延，在无序到有序转变温度以上气相沉积和退火联苯分子adlayer。用于外延排序的最薄 adlayer 为 35 ML，单层，外延达到 5000 ML。异质外延是用对二甲苯衬底和联苯覆盖层证明的。