Of current interest: Tiny junction-type Germanium transistor achieves nearly ideal efficiencies

Significant advances in the development of the transistor,¹ the tiny amplifying crystal, have led to the construction of the “junction transistor,”²⁻⁴ a new device with properties never before achieved in any amplifier. Like the original transistor, it is based on the semiconducting properties of germanium, and requires no vacuum, no glass envelope, and no heating element to cause warmup delay. It consists of a tiny rod-shaped germanium crystal treated so that it embodies a thin electrically positive layer sandwiched between two electrically negative ends.