多结太阳电池辐射损伤的电致发光研究

建立了电致发光测试方法,对一种国产GaInP/GaAs/Ge三结太阳电池1MeV电子辐照后各子电池的辐照特性进行了研究,并与光谱响应结果进行了比较。讨论了GaInP/GaAs/Ge三结太阳电池的辐射损伤机理。     

三元合金Ga_(0.52)In_(0.48)P的时间分辨发光谱

在室温和低温液氮下 ,研究了有序和无序 Ga0 .52 In0 .4 8P的时间分辨发光谱。对实验结果的拟合表明 ,有序 Ga0 .52 In0 .4 8P的发光呈双指数规律衰退。其中快过程对应着有序区域上载流子的复合 ,慢过程则对应着有序区域和无序区域的空间分离中心上载流子的复合。无序 Ga0 .52 In0 .4 8P的发光在室温下呈单指数规律衰退。同时从低温下的时间分辨发光谱还可以看出有序样品的发光峰随着延迟时间的变长而蓝移 ,说明低温下在有序 Ga0 .52In0 .4 8P中存在着载流子从无序区域到有序区域的转移     

AlGaInP/GaInP多量子阱的拉曼光谱

利用LP-MOCVD生长了不同周期的AlGaInP／GaInPMQW样品，并测量了它们的拉曼光谱。由于样品包括了掺杂的电流扩展层和欧姆接触层以及上、下限制层，拉曼光谱中观察到了与掺杂有关的耦合电子(空穴)气-纵光学声子模。根据喇曼光谱的选择定则，结合光致发光谱，发现AIP-LO／TO的相对强度比可以评定晶体AlGaInP MQW的生长质量。     

Stretchable semiconductor technologies with high areal coverages and strain-limiting behavior: demonstration in high-efficiency dual-junction GaInP/GaAs photovoltaics

Notched islands on a thin elastomeric substrate serve as a platform for dual-junction GaInP/GaAs solar cells with microscale dimensions and ultrathin forms for stretchable photovoltaic modules. These designs allow for a high degree of stretchability and areal coverage, and they provide a natural form of strain-limiting behavior, helping to avoid destructive effects of extreme deformations.     

Correlation between dark current RTS noise and defects for AIGalnP multiple-quantum-well laser diode

The correlation model between dark current RTS noise and defects for A1GalnP multiple-quantum-well laser diode is derived. Experimental results show that dark current RTS noise caused carrier number fluctuations at the interface of the heterojunction in the active region. According to this correlation model, the defect types are determined, and the defects＇ energy levels are quantitatively determined. The comer frequency of RTS noise power spectral density is analyzed. The experimental results are in good agreement with the theoretical. This result provided an effective method for estimating the deep-level traps in the active region of A1GaInP multiple quantum well laser diode.     

Positioning and doping effects on quantum dot multi‐junction solar cell performance

The positioning of InAs quantum dot (QD) layers in a triple‐junction GaInP/Ga(In)As/Ge solar cell is studied using numerical modeling techniques. An effective medium is used to describe the absorption characteristics and carrier dynamics in each QD layer. The effects of incorporating 110 layers in the emitter, base layers, as well as between these regions of the middle sub‐cell are analyzed with current–voltage characteristics and energy band diagrams. The cell with QDs positioned between the emitter and base demonstrated an efficiency of 31% under 1 sun illumination at room temperature. The performance was then increased to 31.3% by optimizing the QD region doping. Copyright © 2014 John Wiley & Sons, Ltd.     

Luminescence coupling effects on multijunction solar cell external quantum efficiency measurement

The effects of luminescence coupling on the external quantum efficiency (EQE) measurement of an InGaP/InGaAs/Ge triple junction solar cell were investigated. A small signal model was used to study the interaction of the subcells during EQE measurement. It was found that an optical–electrical feedback mechanism results in EQE measurement artifacts. Measurements of luminescence from the InGaP p–n junction are also performed to quantitatively determine the strength of the luminescence coupling. These results offer a more thorough and comprehensive interpretation of EQE measurement results that are needed for the design and accurate performance evaluation of high‐efficiency multijunction solar cells. The effects demonstrated here can also be used to measure the spontaneous emission efficiency of the subcells, which is useful for nondestructive assessment of multijunction solar cell material quality. Copyright © 2011 John Wiley & Sons, Ltd.     

0.28-2.80 MeV质子辐射对空间实用GaInP/GaAs/Ge多结太阳电池性能的影响

用0.28、0.62和2.80 MeV质子束模拟空间辐射对国产MOCVD方法制备的GaInP/GaAs/Ge多结电池进行质子辐射效应研究.辐照注量为1×1012 cm-2.对电池的辐射效应用I-V特性和光谱响应测试进行分析.结果表明:随质子辐照能量的增加,太阳电池性能参数Isc,Voc,Pmax和光谱响应的衰降幅度均减小,0.28MeV质子辐照引起电池性能衰降最显著;低能质子辐照引起中间GaAs电池光谱响应衰降更明显.     

Lateral Ordering of InAs Quantum Dots on Cross-hatch Patterned GaInP

We report the use of partially relaxed tensile as well as compressively strained GaInP layers for lateral ordering of InAs quantum dots with the aid of misfit dislocation networks. The strained layers and the InAs QDs were characterized by means of atomic force microscopy, scanning electron microscopy, and X-ray reciprocal space mapping. The QD-ordering properties of compressive GaInP are found to be very similar with respect to the use of compressive GaInAs, while a significantly stronger ordering of QDs was observed on tensile GaInP. Furthermore, we observed a change of the major type of dislocation in GaInP layers as the growth temperature was modified.     

Adjusted NIEL calculations for estimating proton-induced degradation of GaInP/GaAs/Ge space solar cells

The non-ionizing energy loss (NIEL) values for protons in solar cells should be modified by taking into account the distribution of the Bragg damage peak in the active region to calculate the corresponding displacement damage dose. In this paper, based upon a thin target approximation, a new approach is presented to modify NIEL values for protons on a GaAs sub-cell. Adjusted NIEL values can be used to estimate the degradation induced by protons on GaInP/GaAs/Ge triple-junction space solar cells.