High-Efficiency and Low-Cost Solar Cells of a New Type, Having Semiconductors Modified with Ultrafine Metal Particles

利用超细金属颗粒修饰n-Si晶片制备了一种新型的光电电化学固态太阳能电池，并对其性能进行了研究。将水表面的超细铂（Pt）粒子的Langmuir-Blodgett层转移到n-Si晶片上，并通过该方法在纳米尺度上控制了Pt粒子在n-Si晶片上的相互分离。通过对开路光电压（V_<OC>）与Pt粒子密度、电池温度以及经Pt粒子修饰的n-Si的空穴扩散长度的依赖关系的定量实验研究，我们发现，在室温下，用小密度Pt粒子修饰的n-Si作为理想的少数载流子二极管，产生非常高的V_<OC>。我们还尝试使用多孔n-Si作为沉积超细Pt岛的方法，并成功获得了0.59V的相当高的V_<OC>。此外，我们对在pt粒子修饰的n-Si上真空沉积铟锡氧化物（ITO）层制备的固态太阳能电池进行了详细的研究，明确了在pt粒子修饰的n-Si上直接沉积ITO层会在Si表面附近产生许多缺陷（表面复合中心），导致V_<OC>'s小，但在ITO沉积之前预沉积薄的酞菁铜层抑制了这种缺陷的形成。增大V_<OC>至0.58V。我们还研究了“ITO/Si-氧化物/Si”太阳能电池，以阐明薄膜和界面的结构和性能。

Photoelectrochemical and solid-state solar cells of a new type, prepared by use of n-Si wafers modified with ultrafine metal particles, have been studied with an aim to improving the characteristics. A Langmuir-Blodgett layr of ultrafine platinum (Pt) particles on a water surface was transferred onto an n-Si wafer and, by this method, the mutual separation of the Pt particles on n-Si was controlled on a nanometer scale, From quantitative experimental studies on the dependences of the open-circuit photovoltage (V_<OC>) on the Pt-particle density and the cell temperature as well as that on the hole diffusion length of n-Si modified with the Pt particles, we have revealed that the n-Si modified with the Pt particles at a small density acts as an ideal minority-carrier diode at room temperature and generates a very high V_<OC>. We also attempted to use porous n-Si as a method to deposit ultrafine Pt islands and succeeded in obtaining a fairly high V_<OC> of 0.59V.Furthermore, we mede detailed studies on the solid-state solar cells prepared by the vacuum deposition of an indium-tin-oxide (ITO) layr on the Pt-particle modified n-Si, and have clarified that the direct deposition of an ITO layr on the Pt-modified n-Si causes many defects (surface recombination centers) near the Si surface, leading to small V_<OC>'s, but the pre-deposition of a thin copper-phthalocyanine layr before the ITO deposition suppresses the formation of such defects, incresing V_<OC> to 0.58V.We also studied "ITO/Si-oxide/Si" solar cells to clarify the structure and properties of the thin films and interfaces.