Holographic Zone Plate and Its Combination Used for Conversion of Solar Energy

An on-axis holographic zone plate or an off-axis holographic zone plate used for the silicon solar cell will have a solar energy conversion factor of 2. 5. And the combination of the two plates will have its conversion factor of 5. Especially for the use of silver halide photographic emulsion, the cost can be cut down dramatically.

Electrodeposition and characterization of Cu2O thin films using sodium thiosulfate as an additive for photovoltaic solar cells

Cuprous oxide （Cu2O） thin films have been grown by electrodeposition technique onto ITO-coated glass substrates from aqueous copper acetate solutions with addition of sodium thiosulfate at 60 ℃ The effects of sodium thiosulfate on the electrochemical deposition of Cu2O films were investigated by cyclic voltammetry and chronoamperometry techniques. Deposited films were obtained at - 0.58 V vs. SCE and characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FrIR）, scanning electron microscopy （SEM）, and optical, photoelectrochemical and electrical measurements. X-ray diffraction results indicated that the synthesized Cu2O films had a pure cubic phase with a marked preferential orientation peak along （200） plane and with lattice constants a = b = c = 0.425 rim. FFIR results confirmed the presence of Cu2O films at peak 634 cm 1. SEM images of Cu2O films showed a better compactness and spherical-shaped composition. Optical properties of Cu2O films reveal a high optical transmission （〉80%） and high absorption coefficient （α 〉 104 cm- 1 ） in visiblelight region. The optical energy band gap was found to be 2.103 eV. Photoelectrochemical measurements indicated that Cu2O films had n-type semiconductor conduction, which confirmed by Hall Effect measurements. Electrical properties of Cu2O films showed a low electrical resistivity of 61.30 Ω. cm-1, carrier concentration of-4.94×1015cm -3andmobility of20.61cm2.V 1,s-l.Theobtained Cu2O thin films with suitable properties are promising semiconductor material for fabrication of photovoltaic solar cells,

Solar-Powered Direct-Current Loads in Small Buildings

Traditional light bulbs （e.g., incandescent, fluorescent） use too much electricity, convert very little energy into light of sufficient quality and in their production use toxic contaminants. During the last few years, a new type of light source, LED （light emitting diode） bulb, has gained increasing popularity and its costs are set to plunge even further. LED bulbs offer many advantages over traditional sources, and they can be used as a direct replacement to existing lighting. This paper will use a spreadsheet-based analysis with hourly solar data supplied by Ecotect to show that, the efficiency of LED installations can be increased when used in conjunction with photovoltaic modules, as the two generate （and use） DC （direct-current） electricity, thereby eliminating intermediate-level losses in the electronic circuitry. If a storage battery is included, the solar panels generate electricity during the times when the occupants are not necessarily using the lighting, but the stored electricity can be used to power the lighting when the energy is required. The latest results demonstrate that, a slight reduction in the required floor area to be lit allows the solar-battery-LED system to be implemented in small buildings using a storage battery size that is within the range of present commercial devices.

Investigation of shunt solar cells’ currents based on equivalent circuit model

In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equivalent one-diode circuit of the solar cell and the analysis of the two-body model. At first, the equations of current and voltage are deduced from the related electrical laws and the circuit diagram of the two solar cells connected in parallel. Then, according to the experimentally measured data of typical single-crystalline silicon solar cells (125 mm×125 mm), we select the appropriate simulation parameters. Following this, by using the photo-generated current, the shunt resistance, and the serial resistance of one of the shunt solar cells and the load resistance as independent variables, in turn, the changing characteristics of each branch current in the two shunt solar cells are numerically discussed and analyzed for these four cases for the first time. At the same time, we provide a simple physical explanation for the modeling results. Our analyses show that these parameters have different impacts on the internal currents of solar cells connected in parallel. These results provide a reference to solve the problem of connecting solar cells and to develop higher efficiency solar cells and systems. Meanwhile, the results will contribute to a better comprehension of the reasons for efficiency loss of solar cells and systems, and deepen the understanding of the electrical of solar cells behavior for high performance photovoltaic applications.

High quality large single crystals of metal halide perovskites for optoelectronic applications

As the technological development of large single-crystalline wafers have revolutionized many industries including electronics and photovoltaics,one can predict that the availability of large single-crystalline perovskite crystals and wafers can revolutionize its broad applications in photodetectors,solar cells,LEDs,lasers,etc.In 2015,Liu et al.