Stabilization of a diamond cold cathode and its application to ultra high sensitive photodetector

在整个研究过程中，我们建立了一个模型来解释重氮掺杂CVD金刚石的电子发射机制。我们不仅研究了多晶样品的电子发射，还研究了同外延和异质外延样品的电子发射。通过a)通过测量阳极和阴极之间距离变化时的发射电流来评估施加在真空上的电场，以及b)从RHEED，霍尔测量，REELS和拉曼光谱的结果，我们证明了我们模型的充分性。在过去的一段时间里，我们比较了表面处理和未表面处理的金刚石样品的发射特性。为了实现我们获得超高灵敏度光电探测器的最终目标，我们使用我们的金刚石发射器作为冷阴极，并使用光导非晶硒（a- se）作为目标。作为一个原型，我们已经制造了一个二极管和三极管结构的光电探测器，并成功地在低于任何已知的传统光电探测器的电压和真空下操作该装置。然而，经过数小时的操作，a- se发生结晶，这降低了性能，尽管发现少量的砷掺杂到硒膜中可以防止这种现象。

Throughout our research we have established a. model to explain the mechanism of the electron emission from heavily nitrogen doped CVD diamonds. We have investigated on the electron emission from not only polycrystalline samples, but also homo- and hetero-epitaxial samples. By a) assessing the electric field applied onto the vacuum by measuring-the emission current when variating the distance between the anode and the cathode, and b) from the results of RHEED, Hall measurement, REELS, and Raman Spectroscopy, we have proved the adequacy of our model. Within the last period, we have compared the emission properties of surface treated and non-surface treated diamond samples.Towards our final goal of obtaining an ultra high sensitive photodetector, we have used our diamond emitter as a cold cathode and a photoconductive amorphous selenium (a-Se) as the target. As a prototype, we have fabricated a diode and triode structured photodeter and succeeded in operating this device under voltage and vacuum lower than any know conventional photodetectors. The a-Se, however experienced crysallization after hours of operation, which decreased the performance, although, a small amount of arsenic doped into the selenium film was found to prevent this phenomena.