claim: The IPhone 4 is only a computer.
evidence: Aluminium arsenide or aluminum arsenide is a semiconductor material with almost the same lattice constant as gallium arsenide and aluminium gallium arsenide and wider band gap than gallium arsenide .. semiconductor material. semiconductor material. lattice constant. lattice constant. gallium arsenide. gallium arsenide. aluminium gallium arsenide. aluminium gallium arsenide. band gap. band gap. can form a superlattice with gallium arsenide which results in its semiconductor properties .. gallium arsenide. gallium arsenide. Because and have almost the same lattice constant , the layers have very little induced strain , which allows them to be grown almost arbitrarily thick .. lattice constant. lattice constant. This allows for extremely high performance high electron mobility , HEMT transistors , and other quantum well devices .