Compared with space parts, consumer parts are highly functional, low cost, compact and lightweight. Therefore, their increased usage in space applications is expected. Prior testing and evaluation on space applicability are necessary because consumer parts do not have quality guarantees for space application [1]. However, in the conventional reliability evaluation method, the test takes a long time, and the problem is that the robustness of the target sample can’t be evaluated in a short time. In this report, we apply to the latest TSOP PEM (Thin Small Outline Package Plastic Encapsulated Microcircuit) an evaluation method that combines preconditioning and HALT (Highly Accelerated Limit Test), which is a test method that causes failures in a short time under very severe environmental conditions. We show that this method can evaluate the robustness of TSOP PEMs including solder connections in a short time. In addition, the validity of this evaluation method for TSOP PEM is shown by comparing with the evaluation results of thermal shock test and life test, which are conventional reliability evaluation methods.

Characterization of Computed Tomography X-Ray ionizing dose will be presented along with a methodology to protect space bound flight hardware from exceeding total ionizing dose (TID) budget prior to mission completion.

A review of the prevalent degradation mechanisms in Lithium ion batteries is presented. Degradation and eventual failure in lithium-ion batteries can occur for a variety of dfferent reasons. Degradation in storage occurs primarily due to the self-discharge mechanisms, and is accelerated during storage at elevated temperatures. The degradation and failure during use conditions is generally accelerated due to the transient power requirements, the high frequency of charge/discharge cycles and differences between the state-of-charge and the depth of discharge influence the degradation and failure process. A step-by-step methodology for conducting a failure analysis of Lithion batteries is presented. The failure analysis methodology is illustrated using a decision-tree approach, which enables the user to evaluate and select the most appropriate techniques based on the observed battery characteristics. The techniques start with non-destructive and non-intrusive steps and shift to those that are more destructive and analytical in nature as information about the battery state is gained through a set of measurements and experimental techniques.

The electronic properties of solar cells, particularly multicrystalline silicon-based ones, are distributed spatially inhomogeneous, where regions of poor quality may degrade the performance of the whole cell. These inhomogeneities mostly affect the dark current-voltage (I-V) characteristic, which decisively affects the efficiency. Since the grid distributes the local voltage homogeneously across the cell and leads to lateral balancing currents, local light beam-induced current methods alone cannot be used to image local cell efficiency parameters. Lock-in thermography (LIT) is the method of choice for imaging inhomogeneities of the dark I-V characteristic. This contribution introduces a novel method for evaluating a number of LIT images taken at different applied biases. By pixel-wise fitting the data to a two diode model and taking into account local series resistance and short circuit current density data, realistically simulated images of the other cell efficiency parameters (open circuit voltage, fill factor, and efficiency) are obtained. Moreover, simulated local and global dark and illuminated I-V characteristics are obtained, also for various illumination intensities. These local efficiency data are expectation values, which would hold if a homogeneous solar cell had the properties of the selected region of the inhomogeneous cell. Alternatively, also local efficiency data holding for the cell working at its own maximum power point may be generated. The amount of degradation of different cell efficiency parameters in some local defect positions is an indication how dangerous these defects are for degrading this parameter of the whole cell. The method allows to virtually 'cut out' certain defects for checking their influence on the global characteristics. Thus, by applying this method, a detailed local efficiency analysis of locally inhomogeneous solar cells is possible. It can be reliably predicted how a cell would improve if certain defects could be avoided. This method is implemented in a software code, which is available.

In this study, the challenges to transfer the microelectronics failure analysis techniques to the photovoltaic industry have been discussed. The main focus of this study was the PHEMOS as a tool with strong technological research capacity developed for microelectronics failure analysis, and OBIC (Optical Beam Induced Current) as a non-destructive technique for detecting and localizing various defects in semiconductor devices. This failure analysis tool was a high resolution optical infrared photon emission microscope used mainly in microelectronics for qualitative analysis and localization of semiconductor defects. Such failure analysis equipment was designed to meet requirements for modern microelectronic devices. Characterization of current photovoltaic device often requires quantitative analysis and should provide information about the electrical and material properties of the solar cell. Therefore, in addition to the demand for further data processing of the obtained results we had to study the corresponding operating regime of solar cells to allow for a correct interpretation of measurement results. In this paper, some of the related problems we faced during this study, e.g. large amount of data processing, the spatial misalignment of the images obtained as EL (Electroluminescence) and IR-LBIC (Infrared Light Beam Induced Current), the implemented laser wavelength, its profile and power density for IR-LBIC measurement. These topics have been discussed in detailed to facilitate a reliable transfer of these techniques from microelectronics to the photovoltaic world.

In this paper, IR-LBIC (Infrared Light Beam Induced Current) is applied using the laser wavelength of 1064 nm in order to analyze polycrystalline thin-film solar cells. The spatially high-resolved map of the short circuit current (~3 µm) has been obtained by performing the IR-LBIC measurement. The results of the measurement showed higher signal response from the grain boundary compared to that from the grain interior. This difference has been explained by the light trapping effect due to the trench-shaped grain boundary profile, which is possibly accompanied by two stage excitation effects via electronic grain boundary states. It has been additionally investigated, whether LBIC measurement could be used to extract local illuminated cell characteristics. However, since the dark current, which has a decisive influence on the solar cell characteristic, is flowing in the entire cell area, this is not possible. A circuit network simulation demonstrates that LBIC cannot be used for extraction of the local open circuit voltage, and the short circuit current is the only parameter that can be locally defined and therefore clearly observed.

Optical or light beam induced current (OBIC or LBIC) are well known techniques for the analysis of integrated circuits and the study of electrically active materials in material science. They are also natural methods for analysis of photovoltaic cells, as the photocurrent of a photovoltaic cell itself is measured. We present a new measurement setup including graphical user interface software which has been created in a student project by refurbishing a used CNC (Computer Numerical Control) milling machine. The technique is applied to the measurement of the short circuit current of a photovoltaic (PV) cell with dimensions of 154 × 154 mm2.

Conventional series resistance imaging methods require electrical contacts for current injection or extraction in order to generate lateral current flow in the solar cell. This paper presents a new method to generate lateral current flow in the solar cell without any electrical contacts. This reduces the sample handling complexity for inline application and allows for measurements on unfinished solar cell precursors.

Crystalline silicon used for fabrication of solar cells, such as multicrystalline silicon (mc-Si), contains a high density of extended crystal defects. Since mc-Si wafers exhibit an inhomogeneous defect distribution, there is a need to combine the spectral capabilities with the ability of spatially resolving the defect areas. This paper reports application of luminescence and electron-beam-induced current (EBIC) techniques for characterization of defects in solar Si. The first part introduces luminescence features of defective Si and discusses application examples. The second part starts with explanation of the EBIC technique, including details about the temperature dependence of the EBIC defect contrast c(T). Then, application examples of the c(T) behavior and the analysis of the "interaction" of grain boundaries with p-n junctions are discussed. The paper demonstrates the potential of luminescence for nondestructive characterization of Si wafers and solar cells in terms of in-line defect detection and process control.

We have developed a process diagnostics system for photovoltaic energy modules based on standard methods and practices already developed for LSI and MEMS technologies. This paper provides a description of methods used to ensure the conformation of solar cell modules to the rigors of high-quality manufacturing necessary for reliable photovoltaic energy production when exposed to long-term environmental use. We have verified the possibility of inspecting each solar cell and the module assembly in detail for several photovoltaic technologies, specifically monocrystalline Si, polycrystalline Si, and CuInxGa1-xSe2 An objective set of criteria for the quality of each module can be provided by this method for use in module selection by consumers. Moreover, the quality of conformance and reliability data can be used as feedback to the manufacturer to minimize the number of defects created during manufacturing process and ameliorate their effects.

A novel analytical method applying combined electron beam induced current (EBIC) imaging based on scanning electron microscopy (SEM) and focused ion beam (FIB) cross sectioning in a SEM/FIB dualbeam system is presented. The method is demonstrated in several case studies for process characterization and failure analysis of thin film technology based Solar cells, including Silicon (CSG), Cadmium Telluride (CdTe) and Copper Indium Selenide (CIS) absorbers. While existing techniques such as electro-, photoluminescence spectroscopy and lock-in thermography are able to locate the larger, electrically active defects reasonably fast on a large area, the FIB-SEM EBIC system is uniquely capable of detecting sub-micron, sub-surface defects and of analysing these defects in the same system. In combination with a FIB, the localized region of interest can be easily cross sectioned and additional EBIC analysis can be applied for a three dimensional analysis of the p/n junction.

The temperature dependence of photocurrent of polycrystalline Si (poly-Si) thin-film solar cells on glass with interdigitated mesa structure has been locally investigated using Infrared Light Beam Induced Current (IR-LBIC) in the temperature range of -25 to +70 °C. The temperature dependence of electrical characteristics of poly-Si thin-film solar cells in reverse bias has been also analysed and compared with the monocrystalline thin-film solar cells. The poly-Si solar cell shows a temperature coefficient (TC) for the photocurrent of around +0.8 and +0.6 %/°C in the grain interior and grain boundary, respectively. The activation energy of the reverse current and also the photocurrent due to the IR laser stimulation has been evaluated, which provide information about traps and their energy levels in the absorber layer of the poly-Si thin-film solar cell. The obtained average value of the activation energy associated with the photocurrent of the poly-Si cell suggests the existence of a shallow acceptor level at around 0.045 eV in the grain boundary and 0.062 eV in the grain interior of the absorber layer of the poly-Si thin-film solar cell. The activation energies of the reverse current for poly-Si and monocrystalline cells have been calculated when the device is biased at -1 and -2 V and the results compared with the activation energy of the saturation current obtained from extrapolation of the I-V curve in the SRH (Shockley-Read-Hall) regime. The results show strong voltage dependence. In both cases the activation energy of the reverse current decreases in the reverse bias voltage, approaching the values obtained from the photocurrent.