Technologies are described effective to implement systems and methods of producing a material. The methods comprise receiving a tertiary semiconductor sample with a dilute species. The sample has two ends. The first end of the sample includes a first concentration of the dilute species lower than a second concentration of the dilute species in the second end of the sample. The method further comprises heating the sample in a chamber. The chamber has a first zone and a second zone. The first zone having a first temperature higher than a second temperature in the second zone. The sample is orientated such that the first end is in the first zone and the second end is in the second zone.