Junction Thin Film Solar Cells Research Articles

Metasurface absorber based single junction thin film solar cell exceeding 30% efficiency.

In this article, we report, as per our knowledge, for the first time, a thin film single junction solar cell with a metasurface absorber layer directly incorporated. We have used an interconnected dual inverted split ring resonator pattern in the InAsP absorber layer. The structure eliminated patterns of conventional metals, such as silver, aluminum, and gold, from the active layer, a common drawback in conventional solar absorbers, hindering their direct integration into solar cells. Optical simulation results show a peak ideal short circuit current density of 76.23mA/cm2 for the meta-absorber structure under solar illumination. This current is the highest among previously reported absorbers based on Group IV materials and III-V compounds, overcoming the low solar absorption of such metasurfaces. The final proposed solar cell structure combines this meta-absorber layer with traditional efficiency enhancement methods namely anti-reflecting coating, textured back reflector, and transparent top electrode. This novel single junction structure shows a solar absorption efficiency of 97.86% and a power conversion efficiency of 30.87%, the highest for III-V solar cells. Our device proves the ability of metasurface absorber layers to produce high-efficiency solar cells and is expected to pave the way for integrating novel meta-devices into state-of-the-art photovoltaic devices, aiding the global transition towards clean energy sources.

Highly flexible radial tandem junction thin film solar cells with excellent power-to-weight ratio

High power-to-weight ratio (PTWR) is an important figure-of-merit for high performance flexible/portable solar cells. Marrying advanced tandem junction design with three-dimensional (3D) Si nanowire (SiNW) framework enables a promising route to boost the PTWR. In this work, a radial tandem junction (RTJ) thin film solar cell has been demonstrated, for the first time, over SiNWs, which consist of radially deposited p-i-n multilayers with hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous silicon germanium (a-SiGe:H) absorption layers in the outer and the inner junctions, respectively. The strong light trapping within the 3D SiNW framework allows for the use of a very thin a-SiGe:H (~45 nm) absorption layer to harvest efficiently the long wavelengths. The RTJ cells fabricated via a one-pump-down process in a single PECVD chamber, directly upon 15 µm thick aluminum foils demonstrate an excellent flexibility that can bend to 10 mm radius and achieve a record PTWR~1628 W/kg, and accomplish a high open-circuit voltage, filling factor and conversion efficiency of 1.2 V, 61.5% and 8.1% on glass, respectively, substantially improved compared to those accomplished by radial single junction cells. These results highlight the unique potential of 3D radial tandem technology to enable a new generation of high performance and durable flexible photovoltaics.

Investigations on Optical, Material and Electrical Properties of aSi:H and aSiGe:H in Making Proposed n+aSi:H/i-aSi:H/p+aSiGe:H Graded Bandgap Single-junction Solar Cell

Objective: This work identifies materials that satisfy refractive index, optical band gap, composition profile, conductivity, hall mobility, carrier type and carrier concentration to utilize them in making thin film photovoltaic cells. Methods: We fabricated phosphorous doped amorphous silicon (n+ aSi:H), boron doped amorphous silicon germanium(p+ aSiGe:H) and intrinsic amorphous silicon (i-aSi:H). A detailed and systematic characterization of the fabricated layers was done. The phosphorous doped amorphous silicon (n+ aSi:H) showed an optical band gap of 1.842 eV and an electron mobility of 295.45 cm2V-1s-1. The boron doped amorphous silicon germanium (p+ aSiGe:H) exhibited an optical band gap of 1.74 eV and a hole mobility of 158.353 cm2V-1s-1. The intrinsic amorphous silicon (i-aSi:H) has an optical band gap of 1.801 eV. The films of n+ aSi:H, i-aSi:H and p+ aSiGe:H can be utilized for fabricating graded band gap single junction thin film solar cells, as they are semiconducting materials with varying band gaps in the range of 1.74 eV to 1.84 eV. The tailoring of band gap achieved by the proposed material combination has been presented using its energy band diagram. Results: In this work, we are proposing a single junction graded band gap solar cell with aSi:H and aSi- Ge:H alloys of varying doping to achieve grading of band gap, which improves the efficiency while keeping the cell compact and light. Conclusion: As a first step in the validation, we have simulated a thin film solar cell using SCAPS1D simulation software with the measured parameters for each of the layers and found that it successfully performs as solar cell with an efficiency of 14.5%.

Plasmonic and photonic enhancement of photovoltaic characteristics of indium-rich InGaN p-n junction solar cells.

In this paper, we demonstrate via Finite-difference time-domain (FDTD) simulations that the performance of indium-rich InxGa1-xN (x = 0.6) p-n junction thin-film solar cells is improved by incorporating an integrated structure of a 2-dimensional (2D) array of ITO nanodiscs on the top surface and a 2D array of Ag nanodiscs in the active layer above the Ag back reflector of the solar cell. The bottom Ag nanodiscs primarily enhance the absorption of longer wavelengths by coupling incident light into surface plasmon resonance (SPR) and waveguide modes. The top ITO nanodiscs enhance the middle wavelengths (400 nm to 800 nm) by coupling the incident light to photonic modes in the active layer. Thus, the integrated structure of nanodisc arrays leads to a very high absorption in the active region in broad spectral range (> 0.85 for wavelengths lying between 350 nm and 800 nm), significantly increasing the short circuit current density (Jsc) and power conversion efficiency (PCE) of the solar cell. In the proposed solar cells, the geometries of the silver and ITO nanodiscs were optimized to obtain the maximum possible values of the Jsc. The highest enhancements in Jsc and PCE of ∼25% and ∼26%, respectively, were obtained in a solar cell containing the integrated structure of ITO and Ag nanodisc arrays. Moreover, the performance of these cells was examined under oblique light incidence and it was observed that the solar cells containing the integrated structure of nanodisc arrays have a significantly larger value of Jsc when compared to the cells having no nanostructures or having only the top ITO nanodisc array or only the bottom Ag nanodisc array.

Coupled boron-doping and geometry control of tin-catalyzed silicon nanowires for high performance radial junction photovoltaics.

Geometry and doping control in silicon nanowires (SiNWs) are both crucial aspects in fabricating three-dimensional (3D) radial junction thin film solar cells, while the coupling between them remains a peculiar aspect to be better understood. In this work, we focus on the geometry evolution and the doping effects realized in tin-catalyzed SiNWs grown via a plasma-enhanced vapor-liquid-solid procedure by using different diborane (B2H6) dopant flows. It is shown that with the increase of B2H6 flow rate from 0.3 to 2.1 SCCM, the radial growth of SiNWs is greatly accelerated by more than 30%, while the length is shortened to 50%. This can be related to the enhanced chemisorption probability of SiHx radicals, with the addition of B2H6, on the SiNW sidewall during silane (SiH4) plasma deposition in PECVD system, which leads to easier nucleation directly on the sidewalls and faster radial expansion of the SiNWs. A trade-off has to be sought between seeking a strong light trapping and ensuring a sufficient doping for high-quality PIN junction with the increase of B2H6 doping flow. These new understandings lay a critical basis for understanding and searching for an optimal growth control for constructing high-performance 3D radial junction thin-film solar cells.

Improved power conversion efficiency in radial junction thin film solar cells based on amorphous silicon germanium alloys

Advanced material combining with novel 3D radial junction design is an attractive strategy to fabricate low-cost high-efficiency thin film solar cells. For improving the power conversion efficiency of traditional a-Si:H thin film solar cells, a conceptually new method incorporating Ge doping technology with 3D radial junction architecture is proposed here. By doping Ge with the optimal amount, the eternal quantum efficiency response of a-Si:Ge alloy thin film solar cell is greatly improved in the near-infrared wavelength. This enhanced spectrum response contributes to the improved power conversion efficiency according to the experimental results and theoretical simulations. On the other hand, by introducing the 3D radial junction architecture, both the excellent light trapping effect and the fast carrier separation contribute to the significantly improved short current density. With the optimal Ge doping amount, the radial junction a-Si:Ge alloy thin film solar cell achieves an open circuit voltage of 0.58 V, short current density of 20.14 mA/cm2, and fill factor of 53.7%, which contributes to the high power conversion efficiency up to 6.26%. From beginning to end, the fabrication temperature is lower than 400 °C and the whole fabrication process shows remarkable compatibility with current photovoltaic industry application. All above results suggest a potential route to the next generation of stable and highly efficient a-Si:H thin film solar cells.

Characteristics of InGaP/GaAs double junction thin film solar cells on a flexible metallic substrate

We have investigated the characteristics of InGaP/GaAs double junction thin film solar cells (TFSCs) on a flexible metallic substrate prepared by electroplating copper (Cu). Both photoluminescence peaks of InGaP and GaAs sub-cells maintained the original positions after transferring the epilayers onto Cu carrier, but a peak shift occurred when the epilayers were bent under intense strain. A slight efficiency improvement up to 29.09% was obtained, compared with 28.25% of conventional structure with GaAs grown substrate under air mass 1.5 (AM1.5) illumination. The TFSCs have a total thickness of about 30 μm, showing an excellent flexibility. Performance measurements of TFSCs were conducted under different strain by bent into the corresponding central angles. It was found that the efficiency was keeping more than 90% when the strain was less than 0.1%, although a rapid decrease down to below 45% occurred till the strain was increased to 0.2%. The favorable performance maintaining after up to 100 bending recycles proved the superior mechanical stability of the TFSCs. Our presented transferring substrate technology based on electroplating in this paper enables the TFSCs with an outstanding performance uniformity, a high yield and a large power weight ratio, which will exhibit an enormous potential to fabricate flexible, low-weight, thin film optoelectronic devices.

Tin dioxide nanoparticles as catalyst precursors for plasma-assisted vapor–liquid–solid growth of silicon nanowires with well-controlled density

The fabrication of arrays of silicon nanowires (Si NWs) with well-defined surface coverage using the vapor–liquid–solid process requires a good control of the density and size distribution for the metal catalyst. We report on a cost-effective bottom-up approach to produce Si NWs by a low-temperature deposition technology using plasma-enhanced chemical vapor deposition and tin dioxide (SnO2) nanoparticles as the source of tin catalyst. This strategy offers a straightforward method to select specific particle sizes by conventional colloidal techniques, and to tune the surface coverage using a polyelectrolyte layer to efficiently immobilize the particles on the substrate by electrostatic grafting. After a further step of reduction into tin metal droplets using hydrogen plasma treatment, the catalyst particles are used for the growth of Si NWs. This approach allows the prodcution of controlled Si NWs arrays which can be used as a template for radial junction thin film solar cells.

Computer analysis of microcrystalline silicon hetero-junction solar cell with lumerical FDTD/DEVICE

The computer analysis of tandem solar cell, c-Si/a-Si:H/[Formula: see text]c-SiGe, is studied within Lumerical FDTD/Device 4.6. The optical characterization is performed in FDTD and then total generation rate is transported into DEVICE for electrical characterization. The electrical characterization of the solar cell is carried out in DEVICE. The design is implemented by staking three sub cells with band gap of 1.12[Formula: see text]eV, 1.50[Formula: see text]eV and 1.70[Formula: see text]eV, respectively. First, single junction solar cell with both a-Si and [Formula: see text]c-SiGe absorbing layers are designed and compared. The thickness for both layers are kept the same. In a single junction, solar cell with a-Si absorbing layer, the fill factor and the efficiency are noticed as [Formula: see text], and [Formula: see text]. For [Formula: see text]c-SiGe absorbing layer, the efficiency and fill factor are increased as [Formula: see text] and [Formula: see text], respectively. Second, for tandem thin film solar cell c-Si/a-Si:H/[Formula: see text]c-SiGe, the fill factor [Formula: see text] and efficiency [Formula: see text] have been noticed. The maximum efficiency for both single junction thin film solar cell c-Si/[Formula: see text]c-SiGe and tandem solar cell c-Si/a-Si:H/[Formula: see text]c-SiGe are improved with check board surface design for light trapping.

Electrodeposition of germanium-containing precursors for Cu2(Sn,Ge)S3 thin film solar cells

Cu2(Sn,Ge)S3 has recently emerged as an absorber layer for single junction thin film solar cells, already achieving power conversion efficiencies of up to 6.7%. Electrodeposition of metallic precursors and their subsequent annealing is an attractive synthesis method for such solar cell absorber layers, since it does not require vacuum conditions and little energy is consumed. The aqueous electrodeposition of metallic germanium based on current knowledge is limited to very thin layers, which do not provide the stoichiometric amount of material required for thick semiconductor layers. Therefore we introduce an electrodeposition method for the growth of germanium-containing precursors for Cu2(Sn,Ge)S3, using propylene-glycol-based electrolytes. These baths do not require additives, give rates of germanium electrodeposition higher than other plating baths and are cheap. The electrochemical behaviour of copper, tin and germanium in propylene glycol was studied and the corresponding deposits were characterised. Smooth and compact layers of each of the pure elements were deposited. Additionally, the co-electrodeposition of copper and germanium was studied as well and thin films containing the alloy Cu3Ge and metallic copper were obtained. A constant [Cu]/[Ge] ratio of around 3 was found over a wide potential range, with a higher plating efficiency than that of pure germanium. For these reasons, copper and germanium were incorporated into the precursor via the referred co-deposition method. After thermal annealing in the presence of elemental sulphur, the semiconductor Cu2(Sn,Ge)S3 was successfully formed and it was incorporated in a working solar cell structure with efficiency of 0.7%

Development of Improved n-μc-SiO$_x$ :H Films and Its Innovative Application in Silicon-Based Single Junction Thin Film Solar Cells

In this paper, we have discussed about the development of high-quality n-μc-SiO:H films by a seeding technique working as a potential back reflector layer (BRL). Highly crystalline and conducting n-μc-Si:H films are used as a seed layer. Phosphorous-doped SiO $_x$ :H film with suitable optoelectronics properties has been deposited by a radio frequency plasma enhanced chemical vapor deposition technique using parallel plate reactors (capacititively coupled). Optoelectronics properties have been controlled and optimized varying the deposition parameters such as process pressure, power density, partial pressure of CO2, etc. We have also innovatively replaced the n-layer, i.e., n-a-Si:H in case of the a-Si:H cell and n-μc-Si:H for μc-Si:H cells by this optimized seed + n-μc-SiO:H films. The performance of this n-μc-SiO:H film grown on the n-μc-Si:H seed layer as n-layer as well as BRL of single junction a-Si:H and μc-Si:H solar cells has been evaluated and better Photovoltaic (PV) characteristics of the solar cell are realized as compared to those of the films developed without any seed layer. a-Si:H solar cells with initial efficiency of 9.38% and μc-Si:H solar cell of 8.50% have been successfully fabricated by using improved doped SiO $_x$ :H based BRL replacing conventional n-layer of the single junction cells.

GenPro4 Optical Model for Solar Cell Simulation and Its Application to Multijunction Solar Cells

We present a new version of our optical model for solar cell simulation: GenPro4 . Its working principles are briefly explained. The model is suitable for quickly and accurately simulating a wide range of wafer-based and thin-film solar cells. Especially adjusting layer thicknesses to match the currents in multijunction devices can be done with a minimum of computational cost. To illustrate this, a triple junction thin-film silicon solar cell is simulated. The simulation results show very good agreement with external quantum efficiency measurements. The application of an MgF2 antireflective coating or an antireflective foil with pyramid texture is considered. Their effects on the implied photocurrents of top, middle, and bottom cells are investigated in detail.

Preparation of NanostructureTiO2 at Different Temperatures by Pulsed Laser Deposition as Solar Cell

Deposition of the Titanium oxide (TiO2) particles on glass and the Si substrates was materialized for a wide range of temperatures (100-400)°C; using PLD technique at constant laser energy 800 mJ of frequency doubled Nd: YAG laser wavelength of 532nm running at 10 Hz rate and 10ns duration pulses. UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM), Atomic Force Microscope(AFM), electrical conductivity (σdc), Hall coefficient (RH) and (I-V) and (C-V) measurements were employed to examine optical, morphological and electrical properties of the deposited films. 85% film transparency was accomplished with optical band gap of (3.25 – 3.64) eV.(I-V) characteristics showedan enhanced TiO2 p-n junction thin film solar cell efficiency by 1.6% at 400°C.

Simulation of the Performance of CdTe/CdS/ZnO Multi- Junction Thin Film Solar Cell

Multi-junction solar cell layers containing CdTe/CdS/ZnO photovoltaic cells were created using SCAP 1D software using parameters based on the previous theoretical characterization to determine the significance effect on the optimization in terms of efficiency on the solar cell. The simulation of the models were carried out by varying the band gap and thickness of the absorber layer and subsequently formulate model equation using regression analysis to determine the efficiency and fill factor at any given value. Result shows that increase in the thickness of absorber layer increases fill factor, current density and open voltage from 83.74- 84.77, 26.26 -28.85mA/cm2, 0.71- 0.73, 15.51 -17.82% that ultimately resulted in a high efficiency of solar cell while increase in band-gap of the absorber layer reduces efficiency of the solar cell. Model equation gives errors ranges between 0.026 – 0.4 for thickness and efficiency, 0.0068 – 0.078 for thickness and fill factor and 0.003 – 0.2 for band gap and efficiency. The study shows that large thickness of absorber layer and low band gap favor the optimization and model equations can be used to estimate/forecast the efficiency and fill factor within the limit of the variable parameters and this offers better direction for laboratory experiment.

Two novel silicon phases with direct band gaps.

Due to its abundance, silicon is the preferred solar-cell material despite the fact that many silicon allotropes have indirect band gaps. Elemental silicon has a large impact on the economy of the modern world and is of fundamental importance in the technological field, particularly in the solar cell industry. Looking for direct band gap silicon is still an important field in material science. Based on density function theory with the ultrasoft pseudopotential scheme in the frame of the local density approximation and the generalized gradient approximation, we have systematically studied the structural stability, absorption spectra, electronic, optical and mechanical properties and minimum thermal conductivity of two novel silicon phases, Cm-32 silicon and P21/m silicon. These are both thermally, dynamically and mechanically stable. The absorption spectra of Cm-32 silicon and P21/m silicon exhibit significant overlap with the solar spectrum and thus, excellent photovoltaic efficiency with great improvements over Fd3[combining macron]m Si. These two novel Si structures with direct band gaps could be applied in single p-n junction thin-film solar cells or tandem photovoltaic devices.

Bi-Sn alloy catalyst for simultaneous morphology and doping control of silicon nanowires in radial junction solar cells

Low-melting point metals such as bismuth (Bi) and tin (Sn) are ideal choices for mediating a low temperature growth of silicon nanowires (SiNWs) for radial junction thin film solar cells. The incorporation of Bi catalyst atoms leads to sufficient n-type doping in the SiNWs core that exempts the use of hazardous dopant gases, while an easy morphology control with pure Bi catalyst has never been demonstrated so far. We here propose a Bi-Sn alloy catalyst strategy to achieve both a beneficial catalyst-doping and an ideal SiNW morphology control. In addition to a potential of further growth temperature reduction, we show that the alloy catalyst can remain quite stable during a vapor-liquid-solid growth, while providing still sufficient n-type catalyst-doping to the SiNWs. Radial junction solar cells constructed over the alloy-catalyzed SiNWs have demonstrated a strongly enhanced photocurrent generation, thanks to optimized nanowire morphology, and largely improved performance compared to the reference samples based on the pure Bi or Sn-catalyzed SiNWs.

Thermal Management in Photo-Electrochemical Hydrogen Generation Devices Using Concentrated Solar Irradaiton

Human activity is overloading the atmosphere with global warming gas emissions which create significant and harmful impacts on our health, environment and climate. Utilizing the ample energy available from renewable sources like sunlight and water, and converting it into chemical energy by photoelectrochemical (PEC) processes, is one viable route to reduce these impacts as life cycle global warming emissions associated with renewable energy are minimal. This presents an effective path for renewable fuel processing and energy storage. Integrated PEC devices, which are composed of an integrated traditional photovoltaics (PV) component and an electrolyzer (EC) component, allow to circumvent some of the challenges imposed by solid-liquid interface in traditional PEC devices, and operate at higher efficiencies than externally wired (non-integrated) PV plus EC devices. To make the integrated devices economically competitive, we have employed concentration of irradiation. We proposed a novel integrated design, shown in fig. 1, combining EC, PV and concentrator [1]. We developed, a coupled 2D multi-physics model of the proposed concentrated PEC device. The model includes radiative heat transfer in the concentrator, electromagnetic wave propagation in the semiconductors (a triple/dual junction solar cell), charge generation and transport in the photoabsorbers and the integrated electrolyzer (polymeric electrolyte and solid electrode), electrochemical reaction at the catalytic sites, fluid flow and species transport in the channels delivering the reactant (water) and removing the products (hydrogen and oxygen), and heat transfer in all components. The detailed simulation flow and coupling between different physical nodes have been shown in fig. 2. Detailed treatment was given for various heat source/sink term calculations for effective thermal management. Urbach tails and defect states in amorphous semiconductors have been incorporated using wxAMPS [2].We completely automatized the simulation flow using multiple interactions between MATLAB Inc., COMSOL and wxAMPS. Efficient computational power saving techniques have been rigorously employed making our model one of the most detailed yet computationally economical. The model proves to be a valuable design and optimization tool for integrated PEC devices working with concentrated irradiation and at elevated temperatures. The model allowed to investigate and optimize the thermal management in the integrated PEC, highlighting that the operating point of the integrated device could be readily shifted to the maximum power point (MPP) of the PV. Thermal management therefore allowed for an efficient and cost effective way of tracking the optimum operating point (OOP), e.g. by controlling the flow rate of water in the water channel for a particular irradiation concentration, providing two distinct benefits: i) reducing the losses by utilizing the generated heat, ii) enabling simple tracking of OOP of the device. The model allowed to conclude that the OOP at a particular concentration was the MPP of the PV and that the OPP of the integrated system was decided by the EC’s current-voltage curve’s saturation part. The mass transport limitations in the EC govern the optical concentration for maximized solar-to-fuel efficiency. The top water channel above the PV not only helps in cooling the PV and supplying the heated reactants to the electrolyser, but it also enhances the optical absorption in the PV by reducing the reflections on top cell surface. The absorption in the water for comparable channel widths is found to be minimal within the absorption spectra of the PV. Parametric studies allowed to find the optimum channel widths governing the absorption and the cooling of device for varying irradiance concentrations. We analysed triple/dual junction thin film solar cells as a cost effective alternative to the earlier studied Ga0.51In0.49P-GaAs-Si [1]. Smart thermal management allowed the design of an integrated device with a dual aSi-ucSi cell to operate at efficiencies comparable to those of Ga0.51In0.49P-GaAs-Si device under non-concentrated irradiation. The model proves to be a valuable tool for the design of integrated PEC cells working with concentrated irradiation at elevated temperatures and highlights that the smart thermal management can help in achieving increased low cost production of solar fuel.

Flexible CdTe/CdS solar cells on thin glass substrates.

We demonstrate flexible CdTe/CdS thin-film solar cells in a superstrate configuration with a cell conversion efficiency as high as 10.9%. We deposit a CdS window layer and a CdTe absorber layer on a flexible glass substrate using the chemical bath deposition method and close-spaced sublimation method, respectively. The thin and flexible glass substrates were able to tolerate a high growth temperature and post-growth processes. We repeatedly apply a strain of 0.15% to the fabricated CdTe/CdS solar cells, and this was shown to have a negligible effect on their performances. Our proposed thin films-on-compliant substrate structure, which was prepared by replacing a rigid glass with a bendable one, demonstrated flexible CdTe/CdS p-n junction thin-film solar cells without compromising the cell performance.

SXPS studies of single crystalline CdTe/CdS interfaces

The interface formation between CdS and CdTe is investigated by synchrotron induced photoemission measurements at the BESSY II storage ring. CdS and CdTe layers were deposited by thermal evaporation on CdTe and CdS single crystal substrates with two different orientations for each substrate. Surface core level shifts show a passivation of dangling bonds for CdS substrates overgrown by CdTe. TeTe bonds are found even on a 200nm thick layer of CdS on CdTe. A valence band offset of 1.02±0.05eV, corresponding to a conduction band offset of −0.09±0.05eV is determined, independent of the substrate type and orientation and in agreement with measurements of polycrystalline interfaces. This alignment of every bands with a very small barrier for electron transfer and a maximized barrier for hole transport to the electron accepting front contact promises ideal properties for devices like CdS/CdTe hetero junction thin film solar cells.

Development of aluminum-doped ZnO films for a-Si:H/μc-Si:H solar cell applications

This study deals with the optimization of direct current (DC) sputtered aluminum-doped zinc oxide (AZO) thin films and their incorporation into a-Si:H/μc-Si:H tandem junction thin film solar cells aiming for high conversion efficiency. Electrical and optical properties of AZO films, i.e. mobility, carrier density, resistivity, and transmittance, were comprehensively characterized and analyzed by varying sputtering deposition conditions, including chamber pressure, substrate temperature, and sputtering power. The correlations between sputtering processes and AZO thin film properties were first investigated. Then, the AZO films were textured by diluted hydrochloric acid wet etching. Through optimization of deposition and texturing processes, AZO films yield excellent electrical and optical properties with a high transmittance above 81% over the 380–1100 nm wavelength range, low sheet resistance of 11 Ω/□ and high haze ratio of 41.3%. In preliminary experiments, the AZO films were applied to a-Si:H/μc-Si:H tandem thin film solar cells as front contact electrodes, resulting in an initial conversion efficiency of 12.5% with good current matching between subcells.