Oxide Sputtering Target for Infrared Transmittance and Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing oxide transparent conductive films used in solar cells face challenges in achieving high photoelectric conversion efficiency and heat-proof humidity resistance due to low transmittance in the infrared region and high carrier-caused reflection, leading to reduced productivity and reliability.
Innovation Solution
A sputtering target composed of an oxide sintered compact with a bixbite-type and perovskite-type oxide phase, specifically formulated with indium, tin, and strontium, is used to form an oxide transparent conductive film with low resistance and high transmittance across a wide wavelength range, minimizing anomalous discharge during sputtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tin-added ITO films are used to achieve low resistance and high transmittance, then electrical conductivity is improved, but optical transparency in the infrared region deteriorates due to high carrier-caused reflection
Solution Approach 1:
The invention changes the compositional parameters by reducing tin content from conventional levels to 0.5-5 atomic percent and introducing strontium at 1-10 atomic percent. This parameter change modifies the carrier concentration and optical properties, achieving both low resistance (0.003-0.03 Ω·cm) and high infrared transmittance by reducing carrier-caused reflection
Solution Approach 2:
The invention creates a composite oxide material system combining indium oxide with controlled amounts of tin oxide and strontium oxide. This composite approach allows synergistic effects where strontium substitution compensates for reduced tin content, maintaining electrical conductivity while improving optical transparency across visible and infrared regions
2Productivity
If anomalous discharge is not suppressed during sputtering, then productivity is reduced due to particle fly-off, but suppressing it requires specific target composition control
Solution Approach 1:
The invention optimizes sputtering target parameters by controlling Sn and Sr content ratios and absolute concentrations. This parameter optimization prevents anomalous discharge by maintaining stable plasma conditions during sputtering, eliminating particle fly-off and improving productivity without adding complex control systems
Solution Approach 2:
The invention converts the potential harm of strontium addition (which could cause discharge instability) into a benefit by carefully controlling Sr content at 1-10 atomic percent. This controlled addition stabilizes the sputtering process, suppresses anomalous discharge, and simultaneously improves film quality and productivity
3Use of energy by moving object
If tin content is reduced to improve infrared transmittance, then optical transparency is improved, but reliability deteriorates
Solution Approach 1:
The invention introduces strontium as an intermediary element that mediates between tin content reduction and reliability maintenance. Strontium substitution at 1-10 atomic percent compensates for reduced tin content by maintaining appropriate carrier concentration, ensuring both high infrared transmittance and film reliability with low resistance
Solution Approach 2:
The invention changes the compositional parameters by reducing tin to 0.5-5 atomic percent while adding strontium at 1-10 atomic percent. This parameter change maintains electrical conductivity and film reliability through strontium-induced carrier concentration control, achieving both improved infrared transparency and sustained reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in a solar cell with enhanced photoelectric conversion efficiency and heat-proof humidity resistance, utilizing sunlight energy efficiently across the infrared region and maintaining high durability and reliability.
Implementation Method 1
a sputtering target composed of an oxide sintered compact with a bixbite-type and perovskite-type oxide phase
Implementation Method 2
an oxide sintered compact with a bixbite-type and perovskite-type oxide phase
Data Source
Figure 1
Figure 2
AI summary
The invention provides an oxide sintered compact 2 composed of a crystal phase which consists of a bixbite-type oxide phase and a perovskite-type oxide phase, or a bixbite-type oxide phase, the crystal phase having indium, tin, strontium and oxygen as the constituent elements, and the indium, the tin and the strontium contents satisfying formulas (1) and (2) in terms of atomic ratio, as well as a sputtering target. There are further provided an oxide transparent conductive film formed using the sputtering target, and a solar cell. Sn/In+Sn+Sr=0.01-0.11 Sr/In+Sn+Sr=0.0005-0.004 [In formulas (1) and (2), In, Sn and Sr represent indium, tin and strontium contents (atomic percent), respectively.]